Dry citrus fibers and uses thereof

ABSTRACT

The invention relates to citrus fibers in dry form having a storage modulus (G′) of at least 50 Pa, said G′ being measured on an aqueous medium containing an amount of 2 wt % citrus fibers dispersed therein under a low-shear stirring of less than 10000 rpm.

FIELD OF INVENTION

The invention relates to citrus fibers and citrus fibers basedcomposition in dry form and in particular to such fibers andcompositions which are readily dispersible. The invention furtherrelates to a method for manufacturing said fibers and compositions andtheir uses.

BACKGROUND

Citrus fibers are known to have many interesting properties making themsuitable for use in a variety of products for human and animalconsumption. Citrus fibers have been successfully employed, mainly astexturizing additives, in food and feed products and beverages, but alsoin personal care, pharmaceutical and detergent products. The use ofcitrus fibers in dry form (hereinafter “dry citrus fibers”) in themanufacturing of the above products is advantageous due to the fibers'longer shelf life and reduced costs of shipping from a fiber productionplant or storage site to a processing facility.

Dry citrus fibers and compositions containing thereof are for exampleknown from WO 2006/033697, WO 2012/016190, and WO 2013/109721. Whencarefully dried, these known citrus fibers may retain an optimum freesurface area available for binding water upon rehydration anddispersion, which in turn provides said fibers with thickeningcapabilities, good stability, and the capacity to create optimumtextures. Using various techniques such as the one disclosed in WO2012/016201, the properties of the dry citrus fibers cart be furthertailored to provide optimum functionalities.

It is however difficult to prepare dry citrus fibers without affectingtheir dispersibility in aqueous media. A method of enhancing thedispersibility of dry citrus fibers in an aqueous medium is tofunctionality or derivative the fibers, i.e. grafting various chemicalmoieties on the surface of the fibers. U.S. Pat. No. 5,964,983 disclosesdry fibres, e.g. citrus fibers, functionalized with acidicpolysaccharides retained on their surface. These fibers however, canonly be dispersed in water with a high-shear mixing device of the ULTRATURRAX type and cannot be thus considered readily dispersible.

Another method known to provide dry, dispersible fibers, involves dryingthe fibers in the presence of additives. U.S. Pat. Nos. 6,485,767 and6,306,207 disclose dry compositions containing up to 20 wt % of apolyhydroxylated compound and dry fibers. Although citrus fibers werementioned as being a suitable example, no experimental data using suchfibers was reported therein. According to the experimental part of thesepublications, somewhat dry fibers (i.e., fibers having a dry substancecontent of about 77 wt % and about 23 wt % moisture) extracted fromsugar beet pulp were readily dispersible in water using only vigorousstirring (500 rpm). However, the properties of these fibers can befurther optimized, in particular their moisture content and/orviscoelastic properties.

It was also observed that known dry compositions containing citrusfibers and additives mas have undesirable characteristics such asstickiness, which in turn may cause problems during a subsequentprocessing thereof. Also, the rheological behavior and viscoelasticstability of such compositions are less than optimum with largevariations in G′ being observed when changing the nature and/or varyingthe amounts of the compositions' constituents.

Accordingly, there is an unmet need in the industry for citrus fibers indry form used as such or in compositions, which can be readily dispersedin an aqueous medium, and which upon dispersion provide said medium withan optimum rheological behavior. More in particular, there is a need fordry citrus fibers used as such or in compositions, which when dispersedin an aqueous medium, provide the aqueous medium with optimum G′ valuesand/or an optimum viscoelastic stability.

SUMMARY OF INVENTION

A primary object of this invention may thus be to provide dry citrusfibers that can be readily dispersed under low-shear stirring in anaqueous medium to form a dispersion having optimum rheologicalproperties.

The foregoing and other objects of this invention are met by providingcitrus fibers in dry form having a storage modulus (G′) of at least 50Pa, said G′ being measured on an aqueous medium containing an amount of2 wt % citrus fiber's dispersed therein under a low-shear stirring ofless than 10000 rpm.

BRIEF DESCRIPTION OF FIGURES

FIGS. 1 and 2 show NMR T₂ distribution curves characteristic to thefibers of the invention upon their dispersal under specific conditionsas detailed herein.

DETAILED DESCRIPTION

Any feature of a particular embodiment of the present invention may beutilized in any other embodiment of the invention. The word “comprising”is intended to mean “including” but not necessarily “consisting of” or“composed of”. In other words, the listed steps or options need not beexhaustive. It is noted that the examples given in the description beloware intended to clarity the invention und are not intended to limit theinvention to those examples per se. Similarly, all percentages areweight/weight percentages unless otherwise indicated. Except in theexamples and comparative experiments, or where otherwise explicitlyindicated, all numbers in this description indicating amounts ofmaterial or conditions of reaction, physical properties of materials andor use are to be understood as modified by the word “about”. Unlessspecified otherwise, numerical ranges expressed in the format “from x toy” are understood to include x and y. When for a specific featuremultiple preferred ranges are described in the format “from x to y”, itis understood that all ranges combining the different endpoints are alsocontemplated. For the purpose of the invention ambient (or room)temperature is defined as a temperature of about 20 degrees Celsius.

In a first aspect, the present invention provides citrus fibers in dryform having a storage modulus (G′) of at least 50 Pa, said G′ beingmeasured on an aqueous medium containing an amount of 2 wt % citrusfibers dispersed therein under a low-shear stirring of less than 10000rpm.

The storage modulus G′ is commonly used in the food industry to analyzethe rheological properties of dispersions and in particular fiber-baseddispersions. In the art, by fiber-based dispersion is understood fibersor compositions containing thereof dispersed in an aqueous medium. G′ isa measure of a deformation energy stored in the dispersion during theapplication of shear forces and provides an excellent indication of thedispersion's viscoelastic behavior. Here, G′ is measured on an aqueousmedium containing an amount of 2 wt % of citrus fibers, i.e. relative tothe total weight of the aqueous medium. It is highly desirable toachieve dispersions having G′ values as high as possible atconcentrations of fibers as low as possible when the fibers aredispersed under low-shear in the aqueous medium.

The present inventors noticed that the citrus fibers of the inventionwere able to meet the above requirements and hence, these novel fibersmay impart food, feed, pharma or personal care formulations containingthereof with optimum theological properties. The novel citrus fibershave also an improved dispersibility in that they are readilydispersible in the aqueous medium. Moreover, since said citrus fibersmay be used at lower concentrations to achieve increased G′ values,food, feed and other manufacturers may have increased design freedom fortheir respective formulations, in that they may be able to add or removeconstituents while maintaining optimum viscoelastic properties thereof.

As used herein, “dispersibility” means that upon dispersion in anaqueous medium, e.g. water, the dry fibers have the capacity to largelyregain their initial functionality, wherein by initial functionality isherein understood the functionality of the fibers before beingdehydrated and/or dried. Properties defining the initial functionalitymay include the fibers' swelling capacity, viscoelasticity,water-binding capacity and stabilization power.

The term “readily dispersible” as used herein means that it is notnecessary to use high-shear means, e.g. high-shear mixers orhomogenizers, to disperse the fibers in an aqueous medium such us waterin order to obtain a useful viscosity; but rather that the dispersion ofthe fibers can be accomplished with low-shear stirring equipment, suchas for example, magnetic stirrers or mechanical stirrers, e.g. an IKA®Eurostat mechanical stirrer equipped with an R1342 4-bladed propellerstirrer or a Silverson L4RT overhead batch mixer equipped with anEmulsor Screen (e.g. with round holes of about 1 mm diameter).

The term “aqueous medium” as used herein means a liquid medium whichcontains water, suitable non-limiting example thereof including purewater, a water solution and a water suspension.

The G′ of the citrus fibers of the invention is at least 50 Pa.Preferably, said G′ is at least 75 Pa, more preferably at least 100 Pa,even more preferably at least 125 Pa, yet even more preferably at least150 Pa, most preferably at least 170 Pa.

The inventors surprisingly observed that the citrus fibers of theinvention manifest the high G′ values upon being dispersed in an aqueousmedium under low shear, i.e. stirring with less than 10000 rpm. This iseven more surprising since said high G′ values were achieved at the lowfiber concentrations, e.g. of 2 wt %. The aqueous medium preferablycontains water in an amount of at least 75 wt %, more preferably atleast 85 wt %, most preferably at least 95 wt %, relative to the totalamount of the medium. Preferably, the stirring used to achieve thedispersion of the fibers of the invention in the aqueous medium is atmost 8000 rpm, more preferably at most 5000 rpm, most preferably at most3000 rpm.

The citrus fibers of the invention are in dry form, which is hereinunderstood as containing an amount of liquid, e.g. water and/or organicsolvent, of less than 20 wt % relative to the total weight of thefibers. Preferably said fibers contain an amount of water (i.e. moisturecontent ) of at most 12 wt %, more preferably at most 10 wt %, or mostpreferably at most 8 wt %. Such dry fibers may be more economical totransport and store while being readily dispersible in the aqueousmedium.

The fibers of the invention are citrus fibers. The term “fiber” as usedherein, refers to an elongated object comprising microfibrils ofcellulose, the fiber having a length (major axis) and a width (minoraxis) and having length to width ratio of at least 5, more preferably atleast 10, or most preferably at least 15, as observed and measured by ahigh-resolution scanning electron microscope (“SEM”). The length of thecitrus fibers is preferably at least 0.5 μm, more preferably at least 1μm. The width of the citrus fibers is preferably at most 100 nm, morepreferably at most 50 nm, most preferably at most 15 nm.

Citrus fibers are fibers contained by and obtained from the fruits ofthe citrus family. The citrus family is a large and diverse family offlowering plants. The citrus fruit is considered to be a specializedtype of berry, characterized by a leathery peel and a fleshy interiorcontaining multiple sections filled with juice filled sacs. Commonvarieties of the citrus fruit include oranges, sweet oranges,clementines, kumquats, tangerines, tangelos, satsumas, mandarins,grapefruits, citrons, pomelos, lemons, rough lemons, limes and leechlimes. The citrus fruit may be early-season, mid-season or late-seasoncitrus fruit. Citrus fruits also contain pectin, common in fruits, butfound in particularly high concentrations in the citrus fruits. Pectinis a gel-forming polysaccharide with a complex structure. It isessentially made of partly methoxylated galacturonic acid, rhamnose withside chains containing arabinose and galactose, which are linked througha glycosidic linkage. The pectin content of the citrus fruit may varybased on season, where ripe fruit may contain less pectin than unripefruit.

Citrus fiber is to be distinguished from citrus pulp, which are wholejuice sacs and are sometimes referred to as citrus vesicles, coarsepulp, floaters, citrus cells, floating pulp, juice sacs, or pulp. Citrusfiber is also to be distinguished from citrus rag, which is a materialcontaining segment membrane and core of the citrus fruit.

The citrus fibers are typically obtained from a source of citrus fibers,e.g. citrus peel, citrus pulp, citrus rag or combinations thereof.Moreover, the citrus fibers may contain the components of the primarycell walls of the citrus fruit such as cellulose, pectin andhemicelluloses and may also contain proteins.

Preferably, the citrus fibers of the invention did not undergo anysubstantial chemical modification, i.e. said fibers were not subjectedto chemical modification processes such us esterification,derivatisation or enzymatic modification and combinations thereof.

Preferably, the citrus fibers in accordance with the invention have acrystallinity of at least 10%, more preferably at least 20%, mostpreferably at least 30% as measured on a dried (less than 20 wt % watercontent relative to the content of fibers) sample by X-ray diffractionmethod (Siegel method). Preferably, the crystallinity of said fibers isbetween 10% and 60%.

The inventors surprisingly found that suitably prepared citrus fibers indry form can be readily dispersed in an aqueous medium by applyingrelatively low levels of shear compared to conventional dry citrusfibers. Without wishing to be bound by theory, it is believed that theexcellent dispersion properties of the citrus fibres are related to thestructure that is imparted on them in the dry form. It was furthersurprisingly found by the present inventors that this structure cansuitably be characterized by a standardized shear storage modulus (G*)that is determined for a standardized dispersion of such citrus fibers.

Consequently, according to a second aspect, the present inventionprovides citrus fibers, in dry form having a G* of at least 50 Pa,wherein G* is measured by:

-   -   a. providing the fibers in a particulate form wherein the        particles can pass a 500 μm sieve by milling the citrus fiber        material using a Waring 8010EG laboratory blender equipped with        an SS110 Pulverizer Stainless Steel Container using its low        speed setting (18000 rpm) for 4 plus or minus 1 seconds; sieving        the milled material using an AS200 digital shaker from Retsch        GmbH Germany with a sieve set of 10 mm, 500 μm, 250 μm and 50 μm        sieves, whilst shaking for 1 minute at an amplitude setting of        60; remilling and resieving the particles larger than 500 μm        until they passed the 500 μm sieve and combining the sieved        fractions;    -   b. dispersing an amount of the fibers in particulate form so as        to obtain 300 grams of an aqueous dispersion comprising 2 wt %        of dry citrus fiber by weight of the dispersion, wherein the        dispersion is buffered at pH 7.0, and whereby the fibers are        dispersed using a Silverson overhead mixer equipped with an        Emulsor screen having round holes of 1 mm diameter at 3000 rpm        tor 120 seconds; and    -   c. determining G* of the resultant dispersion using a parallel        plate rheometer.

Step a. of the above protocol for the determination of G* serves tofacilitate efficient dispersion during step b. The citrus fiber in dryform may come at a variety of particle sizes. Therefore, step a.includes milling of the citrus fiber so as to obtain the fibers in thespecified particulate form. Suitable milling is provided by dry millingusing a laboratory-scale Waring blender. The buffered dispersion of stepb. may be prepared using any suitable buffer system. Preferably, aphosphate-based buffer is used. In step c. the Silverson overhead mixerpreferably is an L4RT overhead mixer. G* is measured using any suitableparallel plate rheometer, for example an ARG2 rheometer of TAInstruments. G* is preferably measured at a strain level of 0.1%. Apreferred way of establishing the G* is by following the protocol in theway described below. The above protocol and the Examples provide methodsof measuring the G*. However, the G* may also be determined by adifferent protocol, as long as that protocol would lead to the samephysical result, i.e. it would yield the same G* for a particular drycitrus fiber preparation as the above protocol.

The citrus fibers in dry form according to the second aspect of theinvention preferably have a G* of at least 100 Pa, more preferably atleast 150 Pa, even more preferably at least 200 Pa, still morepreferably at least 250 Pa, and yet more preferably at least 300 Pa andeven more preferably at least 350 Pa. The citrus fibers in dry formpreferably have a G* of up to 10000 Pa, and more preferably of up to1000 Pa. Thus it is particularly preferred that the citrus fibers in dryform have a G* of between 50 Pa and 10000 Pa, more preferably between300 Pa and 1000 Pa.

In a third aspect, the present invention provides a composition ofmatter in dry form comprising citrus fibers and an additive distributedbetween said fibers, said composition having a storage modulus (G′) ofat least 100 Pa, said G′ being measured on an aqueous medium obtained bydispersing therein an amount of said composition under a low shearstirring of less than 10000 rpm to obtain a citrus fibers' concentrationof 2 wt % relative to the total weight of the aqueous medium.Preferably, G′ is at least 150 Pa, more preferably at least 170 Pa, evenmore preferably at least 190 Pa, yet even more preferably at least 250Pa, yet even more preferably at least 300 Pa, most preferably at least350 Pa when said composition is dispersed under a low shear stirring ofless than 5000 rpm, more preferably less than 3000 rpm. Preferably, G′is at least 375 Pa, more preferably at least 425 Pa, even morepreferably at least 475 Pa, yet even more preferably at least 550 Pa,yet even more preferably at least 600 Pa, most preferably at least 650Pa when said composition is dispersed under a low shear stirring ofbetween 6000 and 10000 rpm, more preferably between 7500 and 8500 rpm.

The composition of the invention, hereinafter the inventive composition,is in dry form, which is herein understood that the composition containsan amount of liquid, e.g. water and/or organic solvent, of less than 20wt % relative to the total weight of said composition. Preferably thecomposition contains an amount of water of at most 12 wt %, morepreferably at most 10 wt %, or most preferably at most 8 wt %. Such adry composition may be more economical to transport and store.

The inventive composition comprises an additive distributed between thecitrus fibers. By the term “additive distributed between the citrusfibers” is herein understood that said additive is distributed inside avolume defined by the totality of fibers and preferably also between themicrofibrils forming the fibers. Preferably, the citrus fibers used inthe inventive composition are the citrus fibers of the invention.

Preferably, the inventive composition contains the additive in an amountof at least 5 wt % relative to the weight of the anhydrous citrus fiberscontained by said composition, more preferably of at least 10 wt %. evenmore preferably of at least 20 wt %, or most preferably of at least 30wt %. The weight of the anhydrous fibers in the composition is theweight of the fibers obtained by drying 10 grams of the compositionwithout the additive at 105° C. under normal atmosphere until constantweight is obtained. The same determination can be carried out in thepresence of the additive; however, in this case the amount of additivein the sample has to be subtracted therefrom. The upper limit for theadditive amount in the inventive composition can be kept within largevariances since it was observed that the citrus fibers contained by saidcomposition may have the ability to optimally include said additive. Apreferred upper limit for the additive amount is at most 1000 wt %relative to the weight of the fibers in said composition, morepreferably at most 750 wt %, or most preferably at most 500 wt %.

Preferably, the inventive composition has an additive:fiber (A:F) ratioof between 0.01:1.0 and 10.0:1.0 by weight, more preferably between0.1:1.0 and 9.0:1.0 by weight, most preferably between 0.4:1.0 and8.0:1.0 by weight. In a first embodiment, the A:F ratio is between0.01:1.0 and 3.8:1.0, more preferably between 0.05:1.0 and 3.4:1.0, mostpreferably between 0.10:1.0 and 3.0:1.0. In a second embodiment, the A:Fratio is between 4.0:1.0 and 10.0:1.0, more preferably between 4.5:1.0and 9.0:1.0, most preferably between 5.0:1.0 and 8.0:1.0. The inventorsobserved that the inventive composition has stable theologicalproperties in that when varying the A:F ratio of the composition, the G′varies with a standard deviation (STDEV) of at most 50% of a maximum(MAX), wherein MAX is the maximum measured value of the G′.

For compositions comprising additives and fibers, G′ may depend on theamount and nature of the fibers but also on the A:F ratio. In otherwords, a composition with a specific A:F ratio has a specific G′ and bychanging said ratio, G′ changes also. The amount with which G′ changeswith the A:F ratio, e.g. as expressed in terms of the standard deviation(STDEV), may give an indication of the dispersibility and thetheological (or viscoelastic) stability of the composition.

The inventors observed that while changing the A:F ratio of theinventive composition, G′ may experience a maximum (MAX); and that thedeviation expressed as STDEV of G′ from MAX for various A:F ratios mayalso give an indication on the dispersibility and the rheologicalstability of the composition. They observed that an increased deviationof STDEV from MAX may deleteriously influence the processability of thecomposition as processing steps with starkly different sets ofparameters may be required for each A:F ratio in order to achieve anoptimal processing thereof. The inventors also observed that variouscharacteristics of the composition such as shelf stability and sensoryperception, including texture and mouthfeel may also be negativelyinfluenced by an increased deviation of STDEV from MAX.

The inventors observed that in the known compositions, additives werenot efficiently mixed with said fibers, which may result in a lessoptimal distribution of the additive between the fibers. This may bereflected by the compositions' less optimal rheological behaviour, e.g.large variations of the compositions' G′ with the A:F ratio and inparticular large deviations of STDEV from MAX.

For the composition of the invention the STDEV characteristic to the G′variations is at most 50% of the MAX. Preferably, the STDEV is at most40% of said MAX, more preferably at most 30% of said MAX, even morepreferably at most 20% of said MAX, most preferably at most 16% of saidMAX. The inventive composition may also be considered readilydispersible. Moreover, the inventors observed that when the A:F ratio isvaried, the obtained G′ values are closely grouped around the MAX; hencethe inventive composition may have a viscoelastic behavior which is lessdependent on the concentration and/or nature of added constituents thanknown citrus fiber-based compositions and may thus offer increaseddesign freedom for products whose rheological or other properties aremodified with the help of these citrus fibers.

The additive used in the inventive composition, is preferably chosenfrom carbohydrates and polyols. Carbohydrates include also derivativesthereof. Preferred carbohydrates are linear or cyclic monosaccharides,oligosaccharides, polysaccharides and fatty derivatives thereof.Examples of fatty derivatives may include sucroesters or fatty acidsucroesters, carbohydrate alcohols and mixtures thereof. Non-limitingexamples of monosaccharides include fructose, mannose, galactose,glucose, talose, gulose, allose, altrose, idose, arabinose, xylose,lyxose and ribose. Non-limiting examples of oligosaccharides includesucrose, maltose and lactose. Non-limiting examples of polysaccharidesinclude nonionic poly saccharides, e.g. galactomannans, such as guargum, carob gum, starch and its nonionic derivatives, and nonioniccellulose derivatives; but also anionic polysaccharides such as xanthangum, succinoglycans, carrageenans and alginates. Preferred examples ofpolyols include without limitation glycerol, pentaerythritol, propyleneglycol, ethylene glycol and/or polyvinyl alcohols. The additivesenumerated above can be used alone or in mixtures or blends of two ormore additives.

In a preferred embodiment, the additive is a hydrophilic additive,suitable examples including dextrins: water-soluble sugars such asglucose, fructose, sucrose, lactose, isomerized sugar, xylose,trehalose, coupling sugar, paratinose, sorbose, reducedstarch-saccharified gluten, maltose, lactulose, fructo-oligosaccharide,galacto-oligosaccharide; hydrophilic starches and sugar alcohols such asxylitol, maltitol, mannitol and sorbitol but also combinations thereof.

In another preferred embodiment, the additive is a starch. The starchused in this invention may be any starch derived from any native source.A native starch as used herein, is one as it is found in nature. Alsosuitable are starches derived from a plant obtained by any knownbreeding techniques. Typical sources for the starches are cereals,tubers and roots, legumes and fruits. The native source can be anyvariety, including without limitation, corn, potato, sweet potato,barley, wheat, rice, sago, amaranth, tapioca (cassava), arrowroot,canna, pea, banana, oat, rye, triticale, and sorghum, as well as lowamylose (waxy) and high amylose varieties thereof. Low amylose or waxyvarieties is intended to mean a starch containing at most 10% amylose byweight, preferably at most 5%, more preferably at most 2% and mostpreferably at most 1% amylose by weight of the starch. High amylosevarieties is intended to mean a starch which contains at least 30%amylose, preferably at least 50% amylose, more preferably at least 70%amylose, even more preferably at least 80% amylose, and most preferablyat least 90% amylose, all by weight of the starch. The starch may bephysically treated by any method known in the art to mechanically alterthe starch, such as by shearing or by changing the granular orcrystalline nature of the starch, and as used herein is intended toinclude conversion and pregelatinization. Methods of physical treatmentknown in the art include ball-milling, homogenization, high shearblending, high shear cooking such as jet cooking or in a homogenizer,drum drying, spray-drying, spray cooking, chilsonation, roll-milling andextrusion, and thermal treatments of low (e.g. at most 2 wt %) and high(above 2 wt %) moisture containing starch. The starch may be alsochemically modified by treatment with any reagent or combination ofreagents known in the art. Chemical modifications are intended toinclude crosslinking, acetylation, organic esterification, organicetherification, hydroxyalkylation (including hydroxypropylation andhydroxyethylation), phosphorylation, inorganic esterification, ionic(cationic, anionic, nonionic, and zwitterionic) modification,succination and substituted succination of polysaccharides. Alsoincluded are oxidation and bleaching. Such modifications are known inthe art, for example in Modified starches: Properties and Uses. Ed.Wurzburg, CRC Press, Inc., Florida (1986).

In another preferred embodiment, the additive is a blend containing afirst additive and a second additive, the first additive being a starchand the second additive being a carbohydrate, a derivatives thereof or apolyol, wherein the second additive is different than the firstadditive. Preferably, the starch is chosen from the group of starchescontaining a native starch, a thermally treated starch, a chemicallymodified starch and combinations thereof. Preferably, the secondadditive is chosen from the group consisting of glucose, sucrose,glycerol and sorbitol.

Most preferred additives for use in the inventive composition areglucose, sucrose, glycerol and sorbitol.

The inventors surprisingly found that a suitably prepared composition ofmatter in dry form, comprising citrus fibers and an additive distributedbetween said fibers can be readily dispersed in an aqueous medium byapplying relatively low levels of shear compared to conventional drycitrus fibers. It was further surprisingly found by the presentinventors that this structure can suitably be characterised by astandardized modulus (G*) that is determined for a standardizeddispersion of the composition of matter. Consequently, according to afourth aspect, the present invention provides a composition of matter indry form comprising citrus fibers and an additive distributed betweensaid fibers, said composition having a G* of at least 150 Pa, wherein G*is measured by

-   -   a. providing the composition in a particulate form wherein the        particles can pass a 500 μm sieve by milling the citrus fiber        material using a Waring 8010EG laboratory blender equipped with        an SS110 Pulverizer Stainless Steel Container using its low        speed setting (114000 rpm) for 4 plus or minus 1 seconds;        sieving the milled material using an AS200 digital shaker from        Retsch GmbH Germany with a sieve set of 10 mm, 500μm, 250 μm and        50 μm sieves, whilst shaking for 1 minute at an amplitude        setting of 60; remilling and retrieving the particles larger        than 500 μm until they passed the 500 μm sieve and combining the        sieved fractions;    -   b. dispersing an amount of the composition in particulate form        so as to obtain 300 grams of an aqueous dispersion comprising 2        wt % of dry citrus fiber by weight of the dispersion, wherein        the dispersion is buffered at pH 7.0, and whereby the fibers are        dispersed using a Silverson overhead mixer equipped with an        Emulsor screen having round holes of 1 mm diameter at 3000 rpm        for 120 seconds; and    -   c. determining G* of the resultant dispersion using a parallel        plate rheometer.

Step a. of the above protocol for the determination of G* serves tofacilitate efficient dispersion during step h. The composition of matterin dry form may come at a variety of particle sizes. Therefore, step a.includes milling of the composition so as to obtain the fibers in thespecified particulate form. Suitable milling is provided by dry millingusing a laboratory-scale Waring blender. The buffered dispersion of stepb. may be prepared using any suitable buffer system. Preferably, aphosphate-based buffer is used. In step c, the Silverson overhead mixerpreferably is an L4RT overhead mixer. G* is measured using any suitableparallel plate rheometer, for example an ARG2 rheometer of TAInstruments. G* is preferably measured at a strain level of 0.1%. Apreferred way of establishing the G* is by following the protocol in theway described below. The above protocol and the Examples provide methodsof measuring the G*. However, the G* may also be determined by adifferent protocol, as long as that protocol would lead to the samephysical result, i.e. it would yield the same G* for a particular drycitrus fiber preparation as the above protocol.

The composition of matter in dry form according to the fourth aspect ofthe invention preferably has a G* of at least 200 Pa, more preferably atleast 250 Pa, even more preferably at least 300 Pa and still morepreferably at least 350 Pa. The composition of matter in dry formpreferably has a Q* of up to 10000 Pa, and more preferably of up to 1000Pa. Thus it is particularly preferred that the composition of matter indry form has a G* of between 150 Pa and 10000 Pa, more preferablybetween 300 Pa and 1000 Pa.

The preferences and examples regarding the citrus fiber, the type andamount of additive in the composition of matter according to this fourthaspect of the invention are as presented hereinabove for the compositionof matter in dry form comprising citrus fibers and an additivedistributed between said fibers according to the present invention. Itis particularly preferred that the additive is sucrose and that theratio A:F of additive to citrus fiber is 0.10 to 1.0 and 3.0 to 1.0 byweight.

In a fifth aspect, the present invention provides cellulose fibers indry form having a transverse relaxation factor as measured by nuclearmagnetic resonance (“NMR”) of at least 0.65. The preferred cellulosefibers are citrus fibers. Preferably, the R₂* of said dry cellulosefibers is at least 0.70, more preferably at least 0.80, even morepreferably at least 0.90, yet even more preferably at least 1.10, andmost preferably at least 1.20. Preferably, the moisture content of thedry cellulose fibers is at most 20 wt % relative to the total mass offibers, more preferably at most 12 wt %, even more preferably at most 10wt %, most preferably at most 8 wt %. To inventors' knowledge, cellulosefibers and in particular citrus fibers dried to a moisture content belowthe above mentioned amounts and having the R₂* in accordance with theinvention were never manufactured hitherto.

The inventors surprisingly observed that R₂* may be used to characterizeand describe dry cellulose fibers and in particular dry citrus fibers.Without being bound to any theory, it is believed that R₂* may providean indication of the magnitude of the available surface area of thefibers. A higher R₂* value thus signifies a larger available surfacearea of a fiber, which in turn may indicate an increased texturizingcapacity of the fibers, i.e. the ability of the fibers to form and orstabilize textures. It was observed that R₂* values, such as thosecharacteristic for the fibers of the invention, were never achievedhitherto, as the publicly reported values and the measured values of anycommercial products existent so far are well below 0.65. It is thusbelieved that the known dry cellulose fibers and in particular the knowndry citrus fibers have a less than optimum texturizing capacity.

The inventors surprisingly found that suitably prepared citrus fibers indry form can be readily dispersed in an aqueous medium by applyingrelatively low levels of shear compared to conventional dry citrusfibers. Likewise, it was surprisingly found that redispersion of asuitably prepared composition of matter in dry form comprising citrusfibers and an additive distributed between said fibers can be dispersedeven more readily. Without wishing to be bound by theory, it is believedthat the excellent dispersion properties of said citrus fibers or saidcomposition in dry form are related to the structure that is imparted onthem in the dry form. It was further surprisingly found by the presentinventors that this structure can suitably be characterised by a FiberAvailability Parameter (FAP). This finding applies to both the citrusfibers in dry form and to the composition of matter in dry form. The FAPis measured using a technique based on NMR. Therefore, according to asixth aspect, the invention provides citrus fibers in dry form having aFAP of at least 0.35 Hz. Similarly, according to a seventh aspect, theinvention provides a composition of matter in dry form comprising citrusfibers and an additive distributed between said fibers having a FAP ofat least 0.70 Hz.

The FAP is determined in essentially the same way for both the citrusfibers according to the sixth aspect and the composition of matter indry form according to the seventh aspect of the invention. Therefore,the term “citrus fiber material” is herein understood to refer to eitherthe citrus fibers in dry form according to the sixth aspect or thecomposition of matter in dry form comprising citrus fibers and anadditive distributed between said fibers according to the seventh aspectof the invention, as the case may be. The FAP provides a measure for theinternal configuration of the citrus fiber material and the extent towhich the fibers are available for redispersion at low shear levels as aresult of that configuration. The FAP is based on the NMR methodperformed on a standardized sample comprising the citrus fiber materialin dispersed form. The FAP of the citrus fiber material is establishedby the following protocol. The protocol to establish FAP includes threeparts: sample preparation, NMR measurement to collectCarr-Purcell-Meiboom-Gill (CPMG) relaxation decay data, and dataanalysis to calculate the FAP value. Thus, the protocol includes thesample preparation steps of:

-   -   a. providing the citrus fiber material in a particulate form        wherein the particles can pass a 500 μm sieve, by milling the        citrus fibre material using a Waring 8010EG laboratory blender        equipped with an SS110 Pulverizer Stainless Steel Container        using its low speed setting (18000 rpm) for 4 plus or minus 1        seconds; sieving the milled material using an AS200 digital        shaker from Retsch GmbH Germany with a sieve set of 10 mm, 500        μm, 250 μm and 50 μm sieves, whilst shaking for 1 minute at an        amplitude setting of 60; remilling and resieving the particles        larger than 500 μm until they passed the 500 μm sieve and        combining the sieved fractions;    -   b. using the citrus fiber material to prepare 300 grams of a        concentration-standardized sample in the form of a dispersion at        room temperature, wherein the concentration-standardized sample        comprises the fibers contained in the citrus fiber material at a        concentration of 0.50 wt-% with respect to the weight of the        standardized sample; by first combining the citrus fiber        material with water to gain a total weight of 250 grams,        optionally adding a preservative, adjusting the concentration of        the sample to a pH of 3.6±0.1 using aqueous hydrochloric acid        and adjusting the volume of the resulting mixture to a total of        300 grams by adding water;    -   c. evenly distributing the fibers inside the        concentration-standardized Sample volume by agitating the sample        using a Silverson overhead mixer equipped with an Emulsor screen        having round holes of 1 mm diameter at 1500 rpm for 120 seconds;    -   d. adjusting the pH of the concentration-standardized sample of        3.3±0.1;    -   e. transferring an aliquot of the concentration- and        pH-standardized sample to a flat-bottom NMR tube of 10 mm        diameter, ensuring a fill height such that upon placement of the        sample in the NMR spectrometer of step h, the fill height is        within the region where the RF field of the coil of the NMR        spectrometer is homogeneous.

Step a. of the above protocol for the determination of the FAP serves tofacilitate efficient dispersion during step b. The citrus fiber materialmay come at a variety of suitable particle sizes. Therefore, step a.includes milling of the citrus fiber material so as to obtain thematerial in the specified particulate form. Suitable milling is providedby dry milling using a laboratory scale Waring blender. The sample ispreferably kept or made free from larger particulate material, includingfor instance fragments of whole or multiple cells and othernon-homogenized material. The distributing step c is intended to providean even distribution of the fibers over the sample volume, whilst havinga controlled effect on the availability of the fibers for dispersion. Instep d, the pH is suitably standardized with the aid of hydrochloricacid. The optimal fill height in step c may depend on the type of NMRspectrometer used, as known by the skilled person. It will typically beabout 1 cm. In the further steps of the protocol, the concentration- andpH-standardized sample will be referred to as the standardized sample.

The data analysis requires comparison of a T₂ distribution curve (seebelow) of the standardized sample with a matrix reference sample, whichshould preferably be essentially free from cellulose fibers. Therefore,the protocol also includes the step of:

-   -   f. preparing a matrix reference sample by centrifuging an        aliquot of the standardized sample in a 2 ml Eppendorf cup at a        relative centrifugation force of 15000 for 10 minutes and        transferring the supernatant to a flat-bottom NMR tube of 10 mm        diameter, ensuring a fill height such that upon placement of the        sample in the NMR spectrometer of step h, the fill height is        within the region where the RF field of the coil of the NMR        spectrometer is homogeneous.

Subsequently, to collect and analyze the data, the protocol includes thesteps of:

-   -   g. equilibrating the NMR tubes at a temperature of 20° C.;    -   h. recording relaxation decay data for the standardized sample        at 20° C. on an NMR spectrometer operating at a proton resonance        frequency of 20 MHz, using a CPMG T₂ relaxation pulse sequence,        with a 180° pulse spacing of 200 microseconds, and a recycle        delay time of 30 seconds;    -   i. recording relaxation decay data for the matrix reference        sample under the same conditions as in step h;    -   j. performing inverse Laplace transformation to the obtained        decay data for both the standardized sample and the matrix        reference sample, requiring T₂ to be in the range of 0.01 to 10        seconds;    -   k. identifying in the T₂ distribution curve of the standardized        sample the peak corresponding to the water protons of which the        T₂ is averaged by exchange between the bulk water phase and the        surface of the defibrillated primary cell wall material and        identifying in the T₂ distribution curve of the matrix reference        sample the peak corresponding to the bulk water phase;    -   l. calculating T₂ (sample), which is defined as the weighted        average T₂ value for the identified peak in the T₂ distribution        curve of the standardized sample and similarly calculating T₂        (matrix) which is defined as the weighted average T₂ value for        the identified peak in the T₂ distribution curve of the matrix        reference sample;    -   m. calculating the values of R₂(sample) and R₂(matrix), where:

R ₂(sample)=1/T ₂(sample), and

R ₂(matrix)=1/T ₂(matrix);

-   -   n. calculating the FAR of the fiber mass as

FAP=R ₂(sample)−R ₂(matrix),

The CPMG T₂ relaxation pulse sequence is well-known in the field of NMRspectroscopy (See Effects of diffusion on free precession in nuclearmagnetic resonance experiments, Carr, H. Y., Purcell, E. M., PhysicalReview, Volume 94, Issue 3, 1954, Pages 630-638/Modified spin-echomethod for measuring nuclear relaxation times, Meiboom, S., Gill, D.,Review of Scientific Instruments, Volume 29, Issue 8, 1958, Pages688-691). Suitable time domain NMR spectrometers to perform this type ofspectroscopy are well-known. Similarly, the usual measures to ensure therecording of reliable data are well-known in the field of time domainNMR spectroscopy. For example, the electromagnetic field should besufficiently homogeneous at the locus where the sample volumes areplaced. The field homogeneity can for example be checked by verifyingwhether a reference sample of pure water, yields a T₂* (T-two-star) forwater protons of more than 2 milliseconds. The inverse Laplacetransformation of step j may suitably be carried out using anon-negative least square constraints algorithm Isqnonneg (Lawson, C. L.and R. J. Hanson, Solving Least Squares Problems, Prentice-Hall, 1974,Chapter 23, p. 161), with the regularization parameter lambda set to0.2. Software packages suitable for implementing the algorithm andcarrying out the transform are well-known, Matlab being an example ofsuch software.

In step k the peak that is selected in the T₂ distribution curs e of thestandardized sample, typically is the dominant peak, if the system issufficiently homogeneous. In general, the peak that should be selectedin the T₂ distribution curve is that corresponding to water protons ofwhich the T₂ is averaged by diffusion and chemical exchange between bulkand surface sites of the dispersed citrus fiber material. This peak isparticularly well-defined if the citrus fibre material is evenlydistributed over the standardized sample. In most typical cases, therewill be only one such peak, as can be seen in the examples in theExamples section below.

The weighted average T₂ in step 1 is for example suitably calculated bythe summation

$\frac{{\sum{I\left( T_{2} \right)}}{\cdot T_{2}}}{\sum{I\left( T_{2} \right)}}$

Here, I(T₂) is the intensity at value T₂ and both summations are overthe width of the peak.

A preferred way of establishing the FAP for the citrus fiber material isby following the protocol in the way described in the Examples sectionbelow. The above protocol and the Examples provide methods of measuringthe FAP. However, the FAP may also be determined by a differentprotocol, as long at that protocol would lead to the same physicalresult, i.e. it would yield the same FAP for a particular citrus fibrematerial as the above protocol.

In summary, the FAP that is determined as described here thus provides ameasure for the degree to which the fibers in the citrus fiber materialare available for redispersion.

The citrus fibres in dry form according to the sixth aspect of theinvention preferably have a FAP of at least 0.35 Hz and more preferablyof at least 0.37 Hz. The citrus fibers preferably have a FAP of at most5.0 Hz, more preferably at most 3.0 Hz and even more preferably at most2.0 Hz.

The composition of matter in dry form according to the seventh aspect ofthe present invention preferably has a FAP of at least 0.60 Hz, morepreferably of at least 0.70 Hz and even more preferably at least 0.74Hz. The composition of matter preferably has a FAP of at most 5.0 Hz,more preferably at most 3.0 Hz and even more preferably at most 2.0 Hz.The preferences and examples regarding the citrus fiber, the type andamount of additive in the composition of matter according to this aspectof the invention are as presented hereinabove for the composition ofmatter in dry form comprising citrus fibers and an additive distributedbetween said fibres according to the present invention. It isparticularly preferred that the additive is sucrose and that the ratioA:F of additive to citrus fiber is 0.10 to 1.0 and 3.0 to 1.0 by weight.

In an eight aspect, the present invention provides cellulose fibers indry form having a self-suspending capacity (SSC) of at least 5%. Thepreferred cellulose fibers are citrus fibers. To inventors' knowledge,no cellulose or citrus fibers produced hitherto had a SSC as high as thefibers of the invention. Preferably, the SSC of the dry cellulose fibersis at least 8%, more preferably at least 12%, even more preferably atleast 15%, yet even more preferably at least 17%, and most preferably atleast 19%. Preferably, the moisture content of the dry cellulose fibersis at most 20 wt % relative to the total mass of fibers, more preferablyat most 12 wt %, even more preferably at most 10 wt %, most preferablyat most 8 wt %. The SSC of fibers may give an indication on how stablemay be a dispersion of said fibers in an aqueous media. A higher SSC offibers may thus indicate that aqueous dispersions containing thereofhave improved stabilities.

The “self-suspending capacity” of a citrus fibre material may bedetermined using the following protocol:

-   -   a. providing the citrus fibre material in a particulate form        wherein the particles can pass a 500 μm sieve; by milling the        citrus fibre material using a Waring 8010EG laboratory blender        equipped with an SS110 Pulverizer Stainless Steel Container        using its low speed setting (18000 rpm) for 4 plus or minus 1        seconds; sieving the milled material using an AS200 digital        shaker from Retsch GmbH Germany with a sieve set of 10 mm, 500        μm, 250 μm and 50 μm sieves, whilst slinking for 1 minute at an        amplitude setting of 60; remitting and resieving the particles        larger than 500 μm until they passed the 500 μm sieve and        combining the sieved fractions:    -   b. preparing a dispersion of the citrus fibre material,        comprising the fibres contained in the citrus fibre material at        a concentration of 0.1 wt-% by agitating the sample using a        Silverson overhead mixer equipped with an Emulsor screen having        round holes of 1 mm diameter at 3000 rpm for 120 seconds;    -   c. filling a 100 ml graded glass measuring cylinder with 100 ml        of said dispersion;    -   d. closing the cylinder and gently turning it up and down for 10        times to ensure a proper wetting of the citrus fiber material    -   c. allowing the citrus fiber material to settle for 24 hours at        room temperature    -   f. visually determining the volume occupied by the cell fiber        material suspension    -   g. calculating the SSC by expressing the volume of step e. as a        percentage of the total volume.

Step a. of the above protocol serves to facilitate efficient dispersionduring step b. The citrus fibre material in dry form may come at avariety of particle sizes. Therefore, step a. includes milling of thecitrus fibre material so as to obtain the fibres in the specifiedparticulate form. Suitable milling is provided by dry milling using alaboratory-scale Waring blender. In step b., the Silverson overheadmixer preferably is an L4RT overhead mixer.

The volume occupied in step f. is suitably determined by opticalinspection. In step g., if for example the volume occupied by the cellwall material suspension is 80 ml, this is expressed as aself-suspending capacity SSC of 80%.

In a ninth aspect, the present invention provides cellulose fibers indry form having a yield stress (YS) of at least 2.0 Pa, said YS beingmeasured on an aqueous medium containing an amount of 2 wt % citrusfibers dispersed therein under a low-shear stirring of less than 10000rpm. YS is measured on an aqueous medium containing an amount of 2 wt %of citrus fibers, i.e. relative to the total weight of the aqueousmedium. The preferred cellulose fibers are citrus fibers. In a preferredembodiment, the fibers are dispersed under a low shear stirring of atmost 3000 rpm. In another preferred embodiment, the fibers are dispersedunder a low shear stirring of between 7000 rpm and 10000 rpm, morepreferably about 8000 rpm and the YS of the dry cellulose fibers is atleast 3.0, more preferably at least 7.0, most preferably at least 10.0.Preferably, the moisture content of the dry cellulose fibers is at most20 wt % relative to the total mass of fibers, more preferably at most 12wt %, even more preferably at most 10 wt %, most preferably at most 8 wt%. The YS may give an indication of the fibers' capacity to influencethe viscoelastic properties of a dispersion containing thereof. A higherYS may indicate that a lower amount of fibers may be needed to achievecertain viscoelastic properties. To inventors' knowledge, no celluloseor citrus fibers produced hitherto and processed into a dispersion underthe conditions presented hereinabove (e.g. rpm, fiber concentration,etc.) had the ability to provide a dispersion containing thereof with YSvalues as high as those provided by the present invention.

In a tenth aspect, the present invention provides citrus fibers in dryform, having a standardized yield stress (YS*) of at least 2.0 Pawherein YS* is measured by

-   -   a. providing the fibers in a particulate form wherein the        particles can pass a 500 μm sieve, by milling the citrus fiber        material using a Waring 8010EG laboratory blender equipped with        an SS110 Pulverizer Stainless Steel Container using its low        speed setting (18000 rpm) for 4 plus or minus 1 seconds; sieving        the milled material using an AS200 digital shaker from Retsch        GmbH Germany with a sieve set of 10 mm, 500 μm, 250 μm and 50 μm        sieves, whilst shaking for 1 minute at an amplitude setting of        60; remilling and relieving the particles larger than 500 μm        until they passed the 500 μm sieve and combining the sieved        fractions;    -   b. dispersing un amount of the fibers in particulate form so as        to obtain 300 grains of an aqueous dispersion comprising 2 wt %        of dry citrus fiber by weight of the dispersion, wherein the        dispersion is buffered at pH 7.0, and whereby the fibers are        dispersed using a Silverson overhead mixer equipped with an        Emulsor screen having round holes of 1 mm diameter at 3000 rpm        for 120 seconds; and    -   c. using a parallel plate rheometer determining the shear        storage modulus G* of the resultant dispersion as a function of        the strain percentage and establishing the YS* from the maximum        of the shear storage modulus G′ versus the strain percentages.

Step a. of the above protocol for the determination of the YS* serves tofacilitate efficient dispersion during step b. The citrus fiber in dryform may come at a variety of particle sizes. Therefore, step a.includes milling of the citrus fiber so as to obtain the fibers in thespecified particulate form. Suitable milling is provided by dry millingusing a laboratory-settle Waring blender. The buffered dispersion ofstep b. may be prepared using any suitable buffer system. Preferably, aphosphate-based buffer is used. In step c the Silverson overhead mixerpreferably is an L4RT overhead mixer. G′ is measured using any suitableparallel plate rheometer, for example an ARG2 rheometer of TAInstruments. G′ is measured at various strain levels as will beunderstood by the skilled person. A preferred wav of establishing theYS* is by following the protocol in the way described below. The aboveprotocol and the Examples provide methods of measuring the YS*. However,the YS* may also be determined by a different protocol, as long as thatprotocol would lead to the same physical result, i.e. it would yield thesame YS* for a particular dry citrus fiber preparation as the aboveprotocol.

The citrus fibres according to the tenth aspect of the inventionpreferably have a YS* of at least 2 Pa, more preferably at least 3 Pa,even more preferably at least 4 Pa and still mere preferably at least4.5 Pa. The citrus fibers preferably have a standardized yield stress ofup to 50 Pa, and more preferably of up to 20 Pa. Thus it is particularlypreferred that the citrus fibers in dry form have a standardized yieldstress of between 2 Pa and 50 Pa, more preferably between 4 Pa and 20Pa.

In an eleventh aspect, the present invention provides a composition ofmatter in dry form comprising citrus fibers and an additive distributedbetween said fibers, said composition having a transverse relaxationfactor (“R₂*”) as measured by nuclear magnetic resonance (“NMR”) of atleast 0.70. Preferably, the R₂* value of said composition is at least0.75, more preferably at least 0.80, even more preferably at least 0.85,most preferably at least 0.90. Preferably, the moisture content of saidcomposition is at most 20 wt % relative to the total mass of fibers,more preferably at most 12 wt %, even more preferably at most 10 wt %,most preferably at most 8 wt %. Preferred examples and preferred amountsof the additive as well as suitable A:F ratios are presented above andwill not be repeated herein.

In a twelfth aspect, the present invention provides a composition ofmatter in dry form comprising citrus fibers and an additive distributedbetween said fibers, said composition having a self-suspending capacity(SSC) of at least 9%. Preferably, the SSC of the composition is at least13%, more preferably at least 15%, even more preferably at least 17%,yet even more preferably at least 19%, and most preferably at least 21%.Preferably, the moisture content of said composition is at most 20 wt %relative to the total mass of fibers, more preferably at most 12 wt %,even more preferably at most 10 wt %, most preferably at most 8 wt %.Preferred examples and preferred amounts of the additive as well assuitable A:F ratios are presented above and will not be repeated herein.

In an thirteenth aspect, the present invention provides a composition ofmatter in dry form comprising citrus fibers and an additive distributedbetween said fibers, said composition having a yield stress (YS) of atleast 2.0 Pa, said YS being measured on an aqueous medium obtained bydispersing an amount of said composition therein under a low shearstirring of less than 10000 rpm to obtain a citrus fibers' concentrationof 2 wt %. YS is measured on an aqueous medium containing an amount of 2wt % of citrus fibers, i.e. relative to the total weight of the aqueousmedium. Preferably, the YS is at least 3.0 Pa, more preferably at least5.0 Pa, even more preferably at least 8.0 Pa, yet even more preferablyat least 10.0 Pa, yet even more preferably at least 12.0 Pa, mostpreferably at least 14.0 Pa. Preferably, the moisture content of saidcomposition is at most 20 wt % relative to the total mass of fibers,more preferably at most 12 wt %, even more preferably at most 10 wt %,most preferably at most 8 wt %. Preferred examples and preferred amountsof the additive as well as suitable A:F ratios are presented above andwill not be repeated herein.

In a fourteenth aspect, the present invention provides a composition ofmatter in dry form comprising citrus fibers and an additive distributedbetween said fibers, said composition having, having a standardizedyield stress (YS*) of at least 2.0 Pa wherein the YS* is measured by

-   -   a. providing the composition in a particulate form wherein the        particles can pass a 500 μm sieve, by milling the citrus fiber        material using a Waring 8010EG laboratory blender equipped with        an SS110 Pulverizer Stainless Steel Container using its low        speed setting (18000 rpm) for 4 plus or minus 1 seconds; sieving        the milled material using an AS200 digital shaker from Retsch        GmbH Germany with a sieve set of 10 mm, 500 μm, 250 μm and 50 μm        sieves, whilst shaking for 1 minute at an amplitude setting of        60; remilling and resieving the particles larger than 500 μm        until they passed the 500 μm sieve and combining the sieved        fractions;    -   h. dispersing an amount of the composition in particulate form        so as to obtain 200 grams of an aqueous dispersion comprising 2        wt % of dry citrus fiber by weight of the dispersion, wherein        the dispersion is buffered at pH 7.0, and whereby the fibers are        dispersed using a Silverson overhead mixer equipped with an        Emulsor screen having round holes of 1 mm diameter at 3000 rpm        for 120 seconds; and    -   c. using a parallel plate rheometer determining the shear        storage modulus G′ of the resultant dispersion as a function of        the strain percentage and establishing the yield stress from the        maximum of the shear storage modulus G′ versus the strain        percentages.

Step a. of the above protocol for the determination of the YS* serves tofacilitate efficient dispersion during step b. The composition of matterin dry form may come at a variety of particle sizes. Therefore, step a.includes milling of the composition so as to obtain the composition inthe specified particulate form. Suitable milling is provided by drymilling using a laboratory-scale Waring blender. The buffered dispersionof step b. may be prepared using any suitable buffer system. Preferably,a phosphate-based buffer is used. In step c. the Silverson overheadmixer preferably is an L4RT overhead mixer. G′ is measured using anysuitable parallel plate rheometer, for example an ARG2 rheometer of TAInstruments. G′ is measured at various strain levels as will beunderstood by the skilled person. A preferred way of establishing theYS* is by following the protocol in the way described below. The aboveprotocol and the Examples provide methods of measuring the YS*. However,the YS* may also be determined by a different protocol, as long as thatprotocol would lead to the same physical result, i.e. it would yield thesame YS* for a particular dry citrus fiber preparation as the aboveprotocol.

The composition of matter in dry form according to the fourteenth aspectof the invention preferably has a YS* of at least 2 Pa more preferablyat least 3 Pa, even more preferably at least 4 Pa and still morepreferably at least 4.5 Pa. The composition of matter in dry formpreferably has a standardized yield stress YS* of up to 50 Pa, and morepreferably of up to 20 Pa. Thus it is particularly preferred that thecomposition of matter in dry form has a standardized yield stress YS* ofbetween 2 Pa and 50 Pa, more preferably between 4 Pa and 20 Pa. Thepreferences and examples regarding the citrus fiber, the type and amountof additive in the composition of matter according to this aspect of theinvention are as presented hereinabove for the composition of matter indry form comprising citrus fibers and an additive distributed betweensaid fibers according to the present invention.

In a fifteenth aspect, the present invention provides a dispersioncomprising citrus fibers dispersed in an aqueous medium, said dispersionhaving a G′ value of at least 50 Pa when measured at a fiberconcentration of 2 wt % relative to the total mass of the dispersion.Preferably, said G′ is at least 100 Pa, more preferably at least 150 Pa,even more preferably at least 200 Pa, yet even more preferably at least250 Pa, most preferably at least 350 Pa. Preferably, said dispersion hasa yield stress (YS) of at least 2.0 Pa, more preferably at least 3.0 Pa,even more preferably at least 5.0 Pa, yet even more preferably at least8.0 Pa, yet even more preferably at least 10.0 Pa, yet even morepreferably at least 12.0 Pa, most preferably at least 14.0 Pa. Examplesof dispersions include without limitation suspensions, emulsions, foamsand the like. The citrus fibers in the dispersion may have a Brownianmotion or they may be fixed at an interface present in the aqueousmedium.

In a sixteenth aspect, the present invention provides a method formanufacturing the inventive fibers and/or compositions comprising thesteps of:

-   -   a. Homogenizing an aqueous slurry of a source of citrus fibers        to obtain an aqueous slurry of citrus fibers:    -   b. Contacting the aqueous slurry of citrus fibers with an        organic solvent to obtain a precipitate phase and a liquid        phase; wherein the precipitate is in the form of granules;    -   c. Separating said precipitate phase from the liquid phase to        obtain a semi-dry citrus fiber cake having a dry        substance-content of at least 10 wt % relative to the mass of        said cake;    -   d. Comminuting said cake to obtain grains containing citrus        fibers; and mixing said grains with an additive to obtain a        semi-dry composition comprising citrus fibers and an additive;        and    -   e. Desolventizing and/or dehydrating said semi-dry composition        to obtain a dry composition containing citrus fibers and an        additive and having a moisture content of preferably below 20 wt        % relative to the total weight of the fibers.

It is difficult to prepare a dry composition containing citrus fiberswithout affecting the composition's dispersibility in an aqueous media.This difficulty is attributed to many factors (collectively referred toin literature as “hornification”) such as the formation of hydrogenbonds an/or lactone bridges between the fibers. Hornification typicallyreduces the available free-surface area of the fibers and/or strengthensthe linkage between the fibers, which in turn may reduce the capacity ofthe fibers to absorb liquid and thus to disperse. Compositionscontaining hornified dry citrus fibers either cannot be dispersed intoan aqueous medium, e.g. water, a water solution or a water suspension,or they can be dispersed only by using high or ultra-high shear mixing.

The method of the invention succeeded however in producing drycompositions wherein the hornification of the citrus fibers was largelyprevented. Without being bound to any theory the inventors believe thatany of the G′, R₂*, SSC and YS as well as the reduced deviations ofSTDEV from MAX characteristic to the inventive fibers and inventivecompositions may indicate a reduced hornification of said fibers.

The method of the invention (the inventive method), contains a step ofhomogenizing an aqueous slurry of a source of citrus fibers (“sourceslurry”). The source of citrus fibers may be citrus peel, citrus pulp,citrus rag or combinations thereof. The source of citrus fibers may be aby-product obtained during the pectin extraction process. Preferably,the source of the citrus fibers is citrus peel; more preferably isde-pectinized citrus peel. Said source slurry preferably comprises a drysubstance content of at least 2 wt %, more preferably at least 3 wt %,more preferably at least 4 wt %. Preferably said dry substance contentof said source slurry is at most 10 wt %, more preferably at most 8 wt%, most preferably at most 6 wt %.

The homogenization of the source slurry may be carried out with a numberof possible methods including, but not limited to high shear treatment,pressure homogenization, cavitation, explosion, pressure increase andpressure drop treatments, colloidal milling, intensive blending,extrusion, ultrasonic treatment, and combinations thereof.

In a preferred embodiment, the homogenization of the source slurry is apressure homogenization treatment which may be carried out with apressure homogenizer. Pressure homogenizers typically comprise areciprocating plunger or piston-type pump together with a homogenizingvalve assembly affixed to the discharge end of the homogenizes. Suitablepressure homogenizers include high pressure homogenizers manufactured byGEA Niro Soavi of Parma (Italy), such as the NS Series, or thehomogenizers of the Gaulin and Rannie series manufactured by APVCorporation of Everett, Mass. (US). During the pressure homogenization,the source slurry is subjected to high shear rates as the result ofcavitation and turbulence effects. These effects are created by thesource slurry entering a homogenizing valve assembly which is part of apump section of the homogenizer at a high pressure (and low velocity).Suitable pressures for the inventive method are from 50 bar to 2000 bar,more preferably between 100 bar and 1000 bar. While not being bound toany theory, it is believed that the homogenization causes disruptions ofthe source of citrus fibers and its disintegration into the fibrouscomponent.

Depending on the particular pressure selected for the pressurehomogenization, and the flow rate of the source slurry through thehomogenizer, the source slurry may be homogenized by one pass throughthe homogenizer or by multiple passes. In one embodiment, the sourceslurry is homogenized by a single pass through the homogenizer. In asingle pass homogenization, the pressure used is preferably from 300bars to 1000 bars, more preferably from 400 bars to 900 bars, even morepreferably from 500 bars to 800 bars. In another preferred embodiment,the source slurry is homogenized by multiple passes through thehomogenizer, preferably at least 2 passes, more preferably at least 3passes through the homogenizer. In a multi-pass homogenization, thepressure used is typically lower compared to a single-passhomogenization and preferably from 100 bars to 600 bars, more preferablyfrom 200 bars to 500 bars, even more preferably from 300 bars to 400bars.

The result of the homogenization step is an aqueous slurry of citrusfibers (“fiber slurry”) comprising a dry substance content of fibers inessentially the same amount as the source slurry. Said fiber slurry isthen contacted with an organic solvent. Said organic solvent shouldpreferably be polar and water-miscible to better facilitate waterremoval. Examples of suitable organic solvents which are polar andwater-miscible include, without limitation, alcohols such as methanol,ethanol, propanol, isopropanol and butanol. Ethanol and isopropanol arepreferred organic solvents; isopropanol is the most preferred organicsolvent for use in the inventive method. The organic solvent can be usedin its 100% pure form or may be a mixture of organic solvents. Theorganic solvent can also be used as a mixture of the organic solvent andwater, hereinafter referred to as an aqueous solvent solution. Theconcentration of organic solvent in said aqueous solvent solution ispreferably from about 60 wt % to about 100 wt % relative to the totalweight of said solution, more preferably between 70 wt % and 95 wt %,most preferably between 80 wt % and 90 wt %. In general, lowerconcentrations of the organic solvent are suitable to remove water andwater-soluble components whereas increasing the concentration of saidorganic solvent also helps in removing oil and oil-soluble components ifdesired. In one embodiment, an organic solvent mixture containing anon-polar organic (NPO) co-solvent and the organic solvent or theaqueous solvent solution is used in the inventive method. Theutilization of the organic solvent mixture may improve for example therecovery of oil-soluble components in the citrus pulp. Examples ofsuitable NPO co-solvents include, without limitation, ethyl acetate,methyl ethyl ketone, acetone, hexane, methyl isobutyl ketone andtoluene. The NPO co-solvents are preferably added in amounts of up to20% relative to the total amount of organic solvent mixture.

The fiber slurry is contacted with the organic solvent preferably in aratio slurry solvent of at most 1:8, more preferably at most 1:6, ormost preferably at most 1:4. Preferably said ratio is at least 1:0.5,more preferably at least 1:1, most preferably at least 1:2. Preferably,said fiber slurry is contacted with the organic solvent for at least 10minutes, more preferably for at least 20 minutes, most preferably for atleast 30 minutes. Preferably, said slurry is contacted with the organicsolvent for at most several hours, more preferably for at most 2 hours,most preferably for at most 1 hour.

According to the invention, said fiber slurry is contacted with saidorganic solvent to obtain a precipitate phase and a liquid phase. Theinventors observed that during contacting the organic solvent with thefibers slurry, the fiber slurry releases at least pan of its watercontent into the organic solvent which in turn causes the citrus fibersto precipitate. By “precipitate phase” is herein understood a phasecontaining the majority of the citrus fibers, e.g. more than 80% of thetotal amount of fibers, preferably more than 90%, most preferably morethan 98% and also containing organic solvent and water. The precipitatephase usually settles due to gravity forces. The precipitate phasetypically has a solid- or a gel-like appearance, i.e. it essentiallymaintains its shape when placed on a supporting surface. By “liquidphase” is herein understood a phase containing organic solvent andwater. The liquid phase may also contain some citrus fibers which didnot precipitate. According to the invention, the precipitate phase is inthe form of granules, preferably, millimeter-size granules. Preferredgranule sizes are between 1 mm and 100 mm, more preferably between 5 mmand 50 mm. By “the size of a granule” is herein understood the biggestdimension of said granule. The formation of the precipitate phase intogranules may be achieved for example by bringing the fiber slurry underagitation into a container containing the organic solvent or by pouringsaid slurry in the organic solvent. The amount of agitation typicallydictates the size of the formed granules. It was observed that byforming granules, the subsequent water removal from said granules isfacilitated. Without being bound to any theory, it is believed that theformation of granules also aids in preserving and-or increasing the freesurface area of the citrus fibers available for water binding and mayalso avoid a collapse of the fibers.

The precipitate phase is subsequently separated from the liquid phase toobtain a semi-dry citrus fibers cake (“fiber cake”). Said separation canbe achieved using known methods such as centrifugation, filtration,evaporation and combinations thereof.

To increase the dry substance content, steps b) and c) of the inventivemethod can be repealed at least one time, preferably before carrying outstep d). The fiber cake can also be subjected to an extraction step. Apreferred extraction method is pressing, e.g. with a normal press, ascrew press or an extruder. A more preferred extraction method ispressure filtration using a volume chamber filter press or a membranefilter press; pressure filters being sold for example by BHS Sonthofen,DE. Two-sided liquid removal is recommended for the pressure filtrationsince more filtering area is available per volume of the fiber cake.

The fiber cake is semi-dry, i.e. it has a dry substance content ofpreferably at least 10 wt %, more preferably of at least 15 wt %, ormost preferably of at least 20 wt % relative to the mass of said cake.Preferably, said cake has a liquid-content of at most 50 wt %, morepreferably at most 40 wt %, most preferably at most 30 wt % relative tothe total mass of said cake. The liquid typically contains organicsolvent and water.

In accordance with the invention, the fiber cake is comminuted to obtaingrains containing citrus fibers (“fiber grains”), said grains preferablyhaving a diameter of at most 100 mm, more preferably at most 50 mm, evenmore preferably at most 30 mm, yet even more preferably at most 10 mm,yet even more preferably at most 5 mm, most preferably at most 3 mm.With “grain diameter” is herein understood the largest dimension of thegrain. The diameter may be determined using a microscope equipped withgraticule. Cutters may be used to cut the fiber cake into grains.Alternatively, the fiber cake can subjected to milling and/or grindingin order to form it into grains. Examples of suitable means to comminutethe fiber cake include without limitation a cutter mill, a hammer mill,a pin mill, a jet mill and the like.

The fiber grains are mixed with an additive to obtain a semi-drycomposition comprising citrus fibers and the additive. Examples ofsuitable additives as well as preferred choices are given above and willnot be repeated herein. Mixing the fiber grains with the additive can beeffected with known means in the an examples thereof including withoutlimitation a malaxer, a transport screw, an air-stream agitation mixer,a paddle mixer, a Z-mixer, a tumble mixer, a high speed paddle mixer, apower blender and the like. The additive may be provided in a solid formor in solution. Preferably, the additive is provided in a solid form,more preferably as a powder, even more preferably as a powder having anaverage particle size (“APS”) of between 100 and 500 μm, more preferablybetween 150 and 300 μm; the APS can be determined by ASTM C136-06.

The semi-dry composition is subjected to a desolventizing and/ordehydrating step wherein the organic solvent and/or the water areextracted from said composition. Preferably, the inventive methodcontains both steps of desolventizing and dehydration. It wassurprisingly observed that during the organic solvent and or waterextraction, the hornification of citrus fibers was largely prevented.Without being bound to any theory, the inventors attributed the reducedhornification to the careful pre-processing of the composition prior tosaid extraction as detailed in steps a) to d) of the inventive method.

Desolventisation and dehydration of said composition can be carried outwith a desolventizer which removes organic solvent and/ or water fromthe composition and may also enable the organic solvent to be reclaimedfor future use. Desolventizing also ensures that the obtained drycomposition is safe for milling and commercial use. The desolventizercan employ indirect heat to remove the organic solvent from thecomposition; the advantage of using said indirect heat is thatsignificant amounts of organic solvents can be extracted. Also, directheat can be provided for drying, e.g. by providing hot air from flashdryers or fluidized bed dryers. Direct steam may be employed, ifdesired, to remove any trace amounts of organic solvent remaining in thecomposition. Vapors from the desolventizer preferably are recovered andfed to a still to reclaim at least a portion of the organic solvent.

Retention times for the desolventizing and/or dehydrating step may varyover a wide range but can be about 5 minutes or less. Suitabletemperatures at which said desolventizing and dehydrating step iscarried out depend on such factors as the type of organic solvent andmost often ranges from about 4° C. to about 85° C. at atmosphericpressure. Temperatures can be appropriately increased or decreased foroperation under supra- or sub-atmospheric pressures. Optionally,techniques such as ultrasound are used for enhancing efficiency of thedesolventizing and dehydrating. By maintaining a closed system, solventlosses can be minimized. Preferably, at least about 70 wt % of theorganic solvent is recovered and reused.

Dehydration can be effected with known means in the art, examplesthereof including without limitation paddle driers, fluidized beddriers, stirred vacuum driers, drum driers, plate driers, belt driers,microwave driers and the like. Preferably, the dehydration temperatureis at most 100° C., more preferably at most 80° C., most preferably atmost 60° C. Preferably, the dehydration temperature is at least 30° C.,more preferably at least 40° C., most preferably at least 50° C.

The desolventizing and/or dehydrating step are carried out to obtain adry composition comprising citrus fibers and an additive, said drycomposition having a moisture content of at most 20 wt % relative to thetotal weight of the fibers, preferably at most 15 wt %, more preferablyat most 12 wt %, even more preferably at most 10 wt %, most preferablyat most 8 wt %.

Optionally, the method of the invention further comprises a step ofremoving said additive and/or classifying the dry composition to obtainthe desired particle size and/or packing the dry composition.

In a preferred embodiment, the inventive method comprises aclassification step of the dry composition which may improve thehomogeneity of the powder, narrow particle size distribution and improvedegree of rehydration. Classification may be carried out using either astatic or dynamic classifier. The inventive method that further comprisea packaging step of the dry composition.

In another preferred embodiment, the additive is extracted from thedried and/or classified composition as obtained at steps f) and/or g),respectively to obtain dry citrus fibers. To aid in the extraction ofthe additive, preferably an additive is used that has a boiling point ofless than the degradation temperature of the citrus fibers. Theextraction may be performed by washing the additive with a suitablesolvent other than water. The extraction is preferably performed bysubjecting said composition to an extraction temperature between theboiling point of the additive and the degradation temperature of thecitrus fibers and allowing the additive to evaporate; preferably theevaporation is carried out under vacuum. Preferably, said additive has aboiling point of at most 250° C., more preferably at most 200° C., mostpreferably at most 150° C. The boiling points of various materials arelisted in the CRC Handbook of Chemistry and Physics or alternatively.ASTM D1120 may be used to determine said boiling point. Preferably theextraction temperature is between 100 and 300° C., more preferablybetween 100 and 250° C., most preferably between 100 and 200° C.Examples of additives having such reduced boiling points include lowmolecular weight polyols, e.g. poly ether polyols, ethylene glycols, andthe like. By low molecular weight is herein understood an M_(w) ofbetween 50 and 500. The use of such extractable additives enables themanufacturing of the inventive fibers. Alternatively, dry citrus fibersmay be obtained with the inventive method by skipping in step d) theaddition of the additive by mixing. Dry cellulose fibers may also beobtained with the method of the invention by choosing an appropriatesource of cellulose fibers to be processed.

The dry composition comprising the citrus fibers and the additive ispreferably milled and/or classified to obtain a powder having an averageparticle size of preferably at least 50 μm, more preferably at least 150μm, most preferably at least 250 μm. Preferably said average particlesize is at most 2000 μm, more preferably at most 1000 μm, mostpreferably at most 50 μm. Said average particle size may be determinedby ASTM C136-06.

In a seventeenth aspect, the invention relates to a composition ofmatter in dry form obtainable by the method for manufacturing thecomposition according to the sixteenth aspect of the present invention.

The invention will be further detailed in the following exemplaryembodiments, without being however limited thereto.

In a first embodiment, the inventive composition of matter in dry formcomprises citrus fibers and an additive distributed between said fibers,wherein said composition has a transverse relaxation factor (R₂*) of atleast 0.70, more preferably of at least 0.75, more preferably of atleast 0.85, most preferably of at least 0.90, wherein when dispersingsaid composition with a low shear stirring of less than 10000 rpm in anaqueous medium to yield a fiber concentration of 2 wt %, the obtaineddispersion has a G′ value of at least 50 Pa. Preferably, the dispersionis carried out with a low shear stirring of at most 8000 rpm, morepreferably at most 5000 rpm, most preferably at most 3000 rpm.Preferably, the A:F ratio of the composition is between 0.01:1 and 10:1by weight, more preferably between 0.1:1 and 9:1 by weight, mostpreferably between 0.4:1 and 8:1 by weight. Preferably, the citrusfibers did not undergo any substantial chemical modification.Preferably, the additive is chosen from the group consisting offructose, mannose, galactose, glucose, talose, gulose, allose, altrose,idose, arabinose, xylose, lyxose, ribose, sucrose, maltose, lactose,glycerol, sorbitol, starch and combinations thereof.

In a second embodiment, the inventive composition of matter in dry formcomprises citrus fibers and an additive distributed between said fibers,wherein said composition has a SSC of at least 9% and a transverserelaxation factor (R₂*) of at least 0.70. Preferably, the SSC of thecomposition is at least 13%, more preferably at least 15%, even morepreferably at least 17%, yet even more preferably at least 19%, and mostpreferably at least 21%. Preferably, the R₂* value of said compositionis at least 0.75, more preferably at least 0.80, even more preferably atleast 0.85, most preferably at least 0.90. Preferably, the A:F ratio ofthe composition is between 0.01:1 and 10:1 by weight, more preferablybetween 0.1:1 and 9:1 by weight, most preferably between 0.4:1 and 8:1by weight. Preferably, the citrus fibers did not undergo any substantialchemical modification. Preferably, the additive is chosen from the groupconsisting of fructose, mannose, galactose, glucose, talose, gulose,allose, altrose, idose, arabinose, xylose, lyxose, ribose, sucrose,maltose, lactose, glycerol, sorbitol, starch and combinations thereof.

In a third embodiment, the citrus fibers of the invention have atransverse relaxation factor (“R₂*”) as measured by nuclear magneticresonance (“NMR”) of at least 0.7 and a self-suspending capacity (SSC)of at least 9%. Preferably, the R₂* value of said dry cellulose fibersis at least 0.9, even more preferably at least 1.1, and most preferablyat least 1.2. Preferably, the SSC of the dry cellulose fibers is atleast 12, even more preferably at least 15, yet even more preferably atleast 17 and most preferably at least 19. Preferably, the moisturecontent of the dry citrus fibers is at most 20 wt % relative to thetotal mass of fibers, more preferably at most 12 wt %, even morepreferably at most 10 wt %, most preferably at most 8 wt %.

In a fourth embodiment, the invention relates to citrus fibers in dryform having a storage modulus (G′) of at least 50 Pa, said G′ beingmeasured on an aqueous medium containing an amount of 2 wt % citrusfibers dispersed therein under a low-shear stirring of less than 10000rpm, said fibers preferably having a transverse relaxation factor(“R₂*”) as measured by nuclear magnetic resonance (“NMR”) of at least0.35, said fibers preferably having a self-suspending capacity (SSC) ofat least 5%, said fibers preferably having a yield stress (YS) of atleast 2.0 Pa, said YS being measured on an aqueous medium containing anamount of 2 wt % citrus fibers dispersed therein under a low-shearstirring of less than 10000 rpm. Preferably, said G′ is at least 75 Pa,more preferably at least 100 Pa, even more preferably at least 125 Pa,yet even more preferably at least 150 Pa, most preferably at least 170Pa. Preferably, the stirring used to achieve the dispersion of saidcitrus fibers in the aqueous medium is at most 8000 rpm, more preferablyat most 5000 rpm, most preferably at most 3000 rpm. Preferably, saidcitrus fibers contain an amount of water of at most 12 wt %, morepreferably at most 10 wt %, or most preferably at most 8 wt %. Preferredranges for R₂*, SSC and YS are presented herein above where the third,fourth and fifth aspects of the invention, respectively, are detailedand will not be further repeated herein.

In a fifth embodiment, the invention relates to a composition of matterin dry form comprising citrus fibers and an additive distributed betweensaid fibers, said composition having a storage modulus (G′) of at least50 Pa, said G′ being measured on an aqueous medium obtained bydispersing an amount of said composition therein under a low shearstirring of less than 10000 rpm to obtain a citrus fibers' concentrationof 2 wt % relative to the total amount of the aqueous medium, saidcomposition preferably having a transverse relaxation factor (“R₂*”) asmeasured by nuclear magnetic resonance (“NMR”) of at least 0.70. saidcomposition preferably having a sell-suspending capacity (SSC) of atleast 9%, said composition preferably having a yield stress (YS) of atleast 2.0 Pa, said YS being measured on an aqueous medium obtained bydispersing an amount of said composition therein under a low shearstirring of less than 10000 rpm to obtain a citrus fibers' concentrationof 2 wt %. Preferably, the composition contains an amount of water of atmost 12 wt %. more preferably at most 10 wt %, or most preferably atmost 8 wt %. Preferably, the composition has an additive:fiber (A:F)ratio of between 0.01:1.0 and 10.0:1.0 by weight, more preferablybetween 0.1:1.0 and 9.0:1.0 by weight, most preferably between 0.4:1.0and 8.0:1.0 by weight. Preferably, the additive is chosen from the groupconsisting of glucose, sucrose, glycerol and sorbitol. Preferred rangesfor G′, R₂*, SSC and YS are presented herein above where the second,sixth, seventh and eighth aspects of the invention, respectively, aredetailed and will not be further repeated herein.

It was observed that the inventive compositions have an optimalviscoelastic stability, e.g. fewer fluctuations of compositions'viscoelastic behavior. The ability of the inventive compositions tosmoothen out viscoelastic fluctuations may enable a more reliableprocessing thereof, which in turn may lead to optimal quality of variousproducts containing said composition, e.g., food, feed, personal careand pharmaceutical products.

The inventive fibers and the inventive compositions are suitably used inthe production of a large variety of food compositions. Examples of foodcompositions comprising thereof, to which the invention relates,include: luxury drinks, such as coffee, black tea, powdered green tea,cocoa, adzuki-bean soup, juice, soya-bean juice, etc.; milkcomponent-containing drinks, such as raw milk, processed milk, lacticacid beverages, etc.: a variety of drinks including nutrition-enricheddrinks, such as calcium-fortified drinks and the like and dietaryfiber-containing drinks, etc.; dairy products, such as butter, cheese,yogurt, coffee whitener, whipping cream, custard cream, custard pudding,etc.; iced products such as ice cream, soft cream, lacto-ice, ice milk,sherbet, frozen yogurt, etc.; processed fat food products, such asmayonnaise, margarine, spread, shortening, etc.; soups, stews;seasonings such as sauce, TARE, (seasoning sauce), dressings, etc.; avariety of paste condiments represented by kneaded mustard; a variety offillings typified by jam and flour paste; a variety or gel or paste-likefood products including red bean-jam, jelly, and foods for swallowingimpaired people; food products containing cereals as the main component,such as bread, noodles, pasta, pizza pie, corn flake, etc.; Japanese, USand European cakes, such as candy, cookie, biscuit, hot cake, chocolate,rice cake, etc.; kneaded marine products represented by a boiled fishcake, a fish cake, etc.; live-stock products represented by ham,sausage, hamburger steak, etc.; daily dishes such as cream croquette,paste for Chinese foods, gratin, dumpling, etc.; foods of delicateflavor, such as salted fish guts, a vegetable pickled in sake lee, etc.;liquid diets such as tube feeding liquid food, etc.; supplements; andpet foods. These food products are all encompassed within the presentinvention, regardless of any difference in their forms and processingoperation at the time of preparation, as seen in retort foods, frozenfoods, microwave foods, etc.

The invention also provides a food composition in dry form, comprisingthe citrus fibre according to the invention and/or the composition ofmatter in dry form according to the invention. Such a food compositionin dry form preferably comprises a composition of matter in dry form,wherein said composition of matter comprises citrus fibres and anadditive distributed between said fibres. It is particularly preferredthat the additive is sucrose and that the ratio A:F of additive tocitrus fibre is 0.10 to 1.0 and 3.0 to 1.0 by weight.

It was surprisingly found that the citrus fibres in dry form of thepresent invention and the composition in dry form comprising citrusfibres and an additive of the present invention can be readily dispersedin an aqueous medium. Therefore, these fibres and compositions canadvantageously be used in the manufacture of compositions comprisingdispersed citrus fibres. Traditionally, exploitation of the propertiesof citrus fibres to prepare a composition with excellent rheologicalproperties requires the use of equipment that can impart high to veryhigh shear during the manufacture of the composition. Such equipment isusually costly, and in operation uses a relatively large amount ofenergy. Moreover, such high shear levels may be detrimental to theproperties of other constituents of such a composition. In particular ifthe product is a food product, for instance, high shear treatment mayadversely affect the taste, flavour and/or other organoleptic propertiesprovided by other ingredients. Using the citrus fibres or composition indry form comprising citrus fibres of the present invention allows themanufacture of intermediate or end products with dispersed citrus fibreswhilst requiring a lower amount of shear energy to obtain the same oreven better benefits of dispersed citrus fibres in the manufacturedproduct. Thus, the citrus fibres and composition of matter in dry formof the present invention provide increased flexibility and efficiency insuch product manufacture.

Consequently, the present invention in an eighteenth aspect provides amethod for preparing a composition comprising an aqueous phase whereinthe aqueous phase comprises dispersed citrus fibres, wherein the methodcomprises the step of dispersing a source of citrus fibres in an aqueousmedium thereby to form at least part of said first aqueous phase; andwherein the source of citrus fibres is citrus fibres in dry formaccording to the present invention or the composition in dry formcomprising citrus fibres and an additive distributed between said fibresaccording to the present invention. The aqueous phase may be preparedwith a variety of rheological properties, and may for instance beselected to have any consistency between highly fluid (water thin) to ahighly viscous, or spoonable, or gelled consistency. The level of citrusfibre in the aqueous phase may suitably be adjusted to the rheologicalrequirements for the particular product. Typically, the aqueous phasemay comprise between 0.01 and 10 wt-% of dispersed citrus fibres withrespect to the weight of the aqueous phase, and preferably comprisesbetween 0.05 and 5 wt-%. even more preferably between 0.1 and 3 wt-% ofdispersed citrus fibres. The source of citrus fibres that is used in thepresent method preferably is a composition of matter in dry formcomprising citrus fibre and an additive distributed between said citrusfibres. It is particularly preferred that the additive is sucrose andthat the ratio A:F of additive to citrus fibre is 0.10 to 1.0 and 3.0 to1.0 by weight. It is likewise preferred that the composition of citrusfibre used as the source of citrus fibre has a Fibre AvailabilityParameter of at least 0.70 Hz, more preferably 0.8 Hz and even morepreferably at least 0.9 Hz.

The present method is particularly useful in the preparation emulsifiedproducts. Therefore, the method preferably is a method for preparing acomposition in the form of an oil-in-water emulsion. The oil-in-wateremulsion is preferably an edible emulsion. The edible oil-in-wateremulsion preferably comprises from 5 to 50 wt-% of oil. The oiltypically is an edible oil. As understood by the skilled person suchedible oils typically comprise triglycerides, usually mixtures of suchtriglycerides. Typical examples of edible oils include vegetable oilsincluding palm oil, rapeseed oil, linseed oil, sunflower oil and oils ofanimal origin.

The present method is also useful to prepare emulsions in the form of adressing or a similar condiment, because it is suitable to providetheological properties that are generally considered desirable fordressings. Since such dressings are typically acidic in nature, thepresent method is preferably for preparing a composition in the form ofan oil-in-water emulsion wherein the composition in the form of anoil-in-water-emulsion comprises from 15 to 50 wt-% of oil and from 0.1to 10 wt-% of acid. It is particularly preferred that the composition inthe form of an oil-in-water emulsion is a mayonnaise.

The present method is also useful in the preparation of emulsifiedproducts which comprise proteins. Thus, the method is preferably amethod for preparing a composition in the form of an oil-in-wateremulsion, wherein the composition in the form of an oil-in-wateremulsion comprises protein, wherein the amount of protein is preferablyfrom 0.1 to 10 wt %, more preferably from 0.2 to 7 wt % and even morepreferably from 0.25 to 4 wt % by weight of the composition. The proteinmay advantageously include milk protein, which is a desirable componentin many food compositions. Thus, the protein preferably comprises atleast 50 wt % milk protein, more preferably at least 70 wt %, even morepreferably at least 90 wt % and still more preferably consistsessentially of milk protein. The suitability of the present method toimpart desirable characteristics deriving from citrus fibres to anaqueous medium, in the presence of both emulsified oil and milk protein,make the method suitable tor the preparation of ready-to-drink milkteas. Hence, the present method preferably is a method for the preparinga composition in the form of an oil-in-water emulsion, wherein thecomposition in the form of on oil-in-water emulsion is a ready-to-drinktea-based beverage. The term “ready-to-drink tea beverage” refers to apackaged tea-based beverage, i.e. a substantially aqueous drinkablecomposition suitable tor human consumption. Preferably the beveragecomprises at least 85% water by weight of the beverage, more preferablyat least 90%. Ready-to-drink (RTD) milk tea beverages usually containmilk solids like for example milk protein and milk fat that give thebeverages certain organoleptic properties like for example a ‘creamymouthfeel’. Such an RTD milk tea beverage preferably comprises at least0.01 wt % tea solids on total weight of the beverage. More preferablythe beverage comprises from 0.04 to 3 wt % tea solids, even morepreferably from 0.06 to 2%, still more preferably from 0.08 to 1 wt %and still even more preferably from 0.1 to 0.5 wt %. The tea solids maybe black tea solids, green tea solids or a combination thereof. The term“tea solids” refers to dry material extractable from the leaves and/orstem of the plant Camellia sinensis, including for example the varietiesCamellia sinensis var. sinensis and/or Camellia sinensis var. assamica.Examples of tea solids include polyphenols, caffeine and amino acids.Preferably, the tea solids are selected from black tea, green tea andcombinations thereof and more preferably the tea solids are black teasolids. In case the method is a method for the preparation of a RTD milktea beverage, the source of citrus fibres that is used preferably is acomposition of matter in dry form comprising citrus fibre and anadditive distributed between said citrus fibres. It is particularlypreferred that the additive is sucrose and that the ratio A:F ofadditive to citrus fibre is 0.10 to 1.0 and 3.0 to 1.0 by weight. It islikewise preferred that the composition of citrus fibre used as thesource of citrus fibre has a Fibre Availability Parameter of at least0.70 Hz, more preferably 0.8 Hz and even more preferably at least 0.9Hz.

The present method is also useful for preparing edible compositionscomprising an aqueous phase, which optionally comprise an oil-basedconstituent, but which do not require the presence of the oil-basedconstituent. Thus, the present method for preparing a compositionwherein the composition comprises at least a first aqueous phasecomprising dispersed citrus fibres preferably is a method for preparinga food composition comprising a flavour base and from 0 wt-% to 5 wt-%of oil, more preferably from 0 wt-% to 2 wt-%. even more preferably from0 wt-% to 1 wt-% and even more preferably from 0 wt-% to 0.5 wt-% of oilwith respect to the weight of the composition. Herein, “flavour base”means the base of the food composition that is responsible for theidentification of the product. The flavour base preferably is a fruit-or vegetable-based product, or a mixture thereof. The present method isespecially useful for imparting desirable rheological characteristics totomato-based products. Therefore, more preferably the flavour base is atomato paste, a tomato puree, a tomato juice, a tomato concentrate or acombination thereof, and even more preferably it is a tomato paste.Thus, present method for preparing a composition comprising an aqueousphase, preferably is a method for the preparation of a compositionwherein the composition is a tomato sauce or a tomato ketchup.

The present method for preparing a composition, wherein the compositioncomprises an aqueous phase comprising dispersed citrus fibres is notlimited to the preparation of edible or food compositions. Theproperties of the citrus fibres in dry form and the composition ofmatter in dry form of the present invention make the present methodparticularly suitable to impart desired rheological properties ontocompositions comprising a surfactant system. Thus, the present inventionalso provides a method for preparing a composition comprising asurfactant system, wherein the composition comprises at least a firstaqueous phase comprising dispersed citrus fibres, wherein the methodcomprises the step of dispersing a source of citrus fibres in an aqueousmedium thereby to form at least part of said first aqueous phase; andwherein the source of citrus fibres is citrus fibres in dry formaccording to the present invention or the composition of matter in dryform comprising citrus fibres and an additive distributed between saidfibres according to the present invention. Preferably, the source ofcitrus fibres is a composition of matter in dry from comprising citrusfibres and an additive distributed between said fibres. It isparticularly preferred that the additive is sucrose and that the ratioA:F of additive to citrus fibre is 0.10 to 1.0 and 3.0 to 1.0 by weight.It is likewise preferred that the composition of citrus fibre used asthe source of citrus fibre has a Fibre Availability Parameter of atleast 0.70 Hz, more preferably 0.8 Hz and even more preferably at least0.9 Hz.

The composition comprising a surfactant system preferably comprises thesurfactant system in an amount of 0.1 to 50 wt-%, more preferably from 5to 30 wt-%, and even more preferably from 10 to 25 wt-% with respect tothe weight of the composition. There are few limitations on the type orthe amount of the surfactants. In general, the surfactants may be chosenfrom the surfactants described in well-known textbooks like “SurfaceActive Agents” Vol. 1, by Schwartz & Perry, Interscience 1949, Vol. 2 bySchwartz, Perry & Berch, Interscience 1958, and/or the current editionof “McCutcheon's Emulsifiers and Detergents” published by ManufacturingConfectioners Company or in “Tenside-Taschcenbuch”, H. Stache, 2^(nd)Edn. Carl Hauser Verlag, 1981; “Handbook of Industrial Surfactants”(4^(th) Edn.) by Michael Ash and Irene Ash; Synapse InformationResources, 2008. The type of surfactant selected may depend on the typeof application for which the product is intended. The surfactant systemmay comprise one type of surfactant, or a mixture of two or moresurfactants. Synthetic surfactants preferably form a major part of thesurfactant system. Thus, the surfactant system preferably comprises oneor more surfactants selected from one or more of anionic surfactants,cationic surfactants, non-ionic surfactants, amphoteric surfactants andzwitterionic surfactants. More preferably, the one or more, detergentsurfactants are anionic, nonionic, or a combination of anionic andnonionic surfactants. Mixtures of synthetic anionic and nonionicsurfactants, or a wholly anionic mixed surfactant system or admixturesof anionic surfactants, nonionic surfactants and amphoteric orzwitterionic surfactants may all be used according to the choice of theformulator for the required cleaning duty and the required dose of thecleaning composition. Preferably, the surfactant system comprises one ormore anionic surfactants. More preferably, the surfactant systemcomprises one or more anionic surfactants selected from the groupconsisting of lauryl ether sulfates and linear alkylbenzene sulphonates.

For certain applications the composition comprising a surfactant systempreferably also comprises from 1 to 8 wt-% of an inorganic salt,preferably selected from sulfates and carbonates, more preferablyselected from MgSO₄ and Na₂SO₄ and even more preferably MgSO₄. Thecomposition comprising a surfactant system may be any product comprisingsurfactants. Preferably the composition comprising a surfactant systemis a cleaning composition, more preferably a hand dish wash composition.In view of the favourable properties that the present method provides tothe composition comprising the surfactant system, the compositionpreferably further comprises suspendable particles and/or air bubbles.

According to a nineteenth aspect, the invention also relates to acomposition comprising a surfactant system wherein the composition alsocomprises the citrus fibre according to the invention and/or thecomposition of matter in dry form according to the invention. Herein,the surfactant system is as described above. The composition comprisinga surfactant system preferably is a composition in dry form. Such acomposition in dry form preferably comprises a composition of matter indry form, wherein said composition of matter comprises citrus fibres andan additive distributed between said fibres. It is particularlypreferred that the additive is sucrose and that the ratio A:F ofadditive to citrus fibre is 0.10 to 1.0 and 3.0 to 1.0 by weight.

Methods of Measurement

-   -   Sample Preparation: It is preferred that prior to any        characterization, all citrus fibers' and compositions' samples        made in accordance with the Examples and Comparative Experiments        presented herein below, are milled using a Waring 8010EG        laboratory blender (Waring Commercial, USA) equipped with a        SS110 Pulverizer Stainless Steel Container using its low speed        setting (18000 rpm) for 3 to 5 sec. The milled samples were        sieved using a AS200 digital shaker from Retsch GmbH Germany        with a sieve set of 10 mm, 500 μm, 250 μm and 50 μm sieves        (50×200 mm), sieving conditions: 1 min at amplitude setting 60.        Particles large than 500 μm may be milled again until they pass        sieve 500 μm.    -   Moisture content (“MC”): The moisture content was determined by        weighing a milled sample placed in a pre-dried vessel and        subsequently heating the vessel containing the sample overnight        in an oven at 105° C. The moisture content (in wt %) was        calculated as (A₁−A₂)/A₁×100 where A₁ was the weight of the        sample before doing in the oven and A₂ was the weight of the        resulted dried sample, unless indicated otherwise.

Dry substance content (“DS”) is measured according to formula:

DS (%)=100%−MC (%)

When the weight of anhydrous fibers in a composition needs to bedetermined, the above procedure can be utilized while correcting themoisture content for the additive content in the sample.

-   -   Standard deviation is computed according to the following        formula:

$\sqrt{\frac{\sum\left( {x - \overset{\_}{x}} \right)^{2}}{\left( {n - 1} \right)}}$

where x is the sample mean average and n is the sample size.

-   -   R₂* measurements:        -   Sample preparation for NMR measurements: dispersions having            fiber concentrations of 0.50 wt % were prepared by            rehydrating milled and sieved samples in demineralized            water. For each dispersion, an appropriate amount of sample            (correcting for moisture and additive content) was weighed            in 500 ml plastic pots and demineralized water was added to            yield a total weight of 250 g. After subsequently adding            0.24 g of a preservative (Nipacide BIT20) and adjusting the            pH to 3.6±0.1 using aqueous HCl, a further amount of            demineralized water was added to yield a mixture with a            total weight of 300 g. This mixture was homogenized at room            temperature using a Silverson L4RT overhead batch mixer,            equipped with an Emulsor Screen (with round holes of about 1            mm diameter) operated for 2 min (120 sec.) at 3000 rpm. The            mixtures were allowed to equilibrate overnight, after which            the pH was standardized at 3.3±1 using concentrated HCl.        -   Calibration: an aliquot of the resulting pH-standardized            mixture was transferred directly to a 18 cm flat bottom NMR            tube of 10 mm diameter at a filling height of about 1 cm            ensuring that upon placement of the sample in the NMR            spectrometer, the fill height is within the region where the            RF field of the coil of the NMR spectrometer is homogeneous.            In order to do a background correction (calibration),            another aliquot was centrifuged (Eppendorf Centrifuge 5416)            for 10 min in a 2 ml Eppendorf cup at a relative            centrifugation force of 15000 to separate the fibers from            the liquid. The top layer (supernatant) of the centrifuged            mixture without the fibre (hereinafter referred to as the            “matrix reference sample”) was transferred to a 18 cm flat            bottom NMR tube at a filling height of 1 cm. Both the            mixture and the matrix reference sample were incubated and            equilibrated at 20° C. for 10 min. prior to the NMR            measurement. The “relative centrifugal force”, is defined as            r×ω²/g, where g=9.8 ms⁻² is the Earth's gravitational            acceleration, r is the rotational radius of the centrifuge,            ω is the angular velocity in radians per unit time. The            angular velocity is ω=rpm×2π/60, where rpm is the number of            “revolutions per minute” of the centrifuge.        -   NMR measurement: Carr Purcell Meiboom Gill (CPMG) relaxation            decay data were collected for each mixture and for each            matrix reference sample. A Bruker MQ20 Minispec was used            operating at a resonance frequency for protons of 20 MHz,            equipped with a variable temperature probe-head stabilized            at 20° C. Measurements were performed using a CPMG T₂            relaxation pulse sequence to observe the relaxation decay at            20° C. (See Effects of diffusion on free precession in            nuclear magnetic resonance experiments, Carr, H. Y.,            Purcell, E. M., Physical Review, Volume 94, Issue 3, 1954,            Pages 630-638/Modified spin-echo method for measuring            nuclear relaxation times, Meiboom, S., Gill. D., Review of            Scientific Instruments, Volume 29, Issue 8, 1958, Pages            688-691). Data were collected with the 180° pulse spacing            set to 200 μs (microseconds), a recycle delay time of 30            sec. a 180°-pulse length of 5 μs and using 14.7k            180°-pulses. The sequence deploys a phase cycle and complex            mode detection. Prior to measurement, the suitability of the            NMR system for these measurements (in terms of field            homogeneity etc.) was checked by verifying that the T₂* of            pure water was ≥2 ms.        -   NMR data analysis (R₂* extraction): Data were processed with            Matlab using a singular value decomposition to phase correct            the quadrature data (“Towards rapid and unique curve            resolution of low-field NMR relaxation data: trilinear            SLICING versus two-dimensional curve fitting”, Pedersen. H.            T., Bro, R., Engelsen, S. B., Journal of Magnetic Resonance,            08/2002; 157(1), Pages 141-155, DOI:            10.1006/jmre.2002.2570). The resulting, phase-corrected data            were Inverse Laplace Transformed into a T₂ spectrum using            the Matlab non-negative least square constraints function            Isqnonneg (Lawson, C. L. and R. J. Hanson, Solving Least            Squares Problems, Prentice-Hall, 1974, Chapter 23, p. 161)            with boundaries set for T₂, requiring T₂ to be in the range            of 0.01 to 10 seconds and with the regularization parameter            lambda set to 0.2.        -    R₂* was determined us follows: from the T₂ distribution            curve for a particular mixture, the peak corresponding to            the water protons of which T₂ is averaged by exchange            between the bulk water phase and the surface of the fiber            material originating from the fiber mass was identified.            Without being bound to any theory, the inventors believe            that the exchange (and resulting averaging) is due to            diffusion and chemical exchange between bulk and fibers'            surface sites. The peaks of the bulk water phase are easily            distinguished, as typically they are the peaks with the            highest intensity. The peak corresponding to the bulk water            phase in the matrix reference sample was similarly            identified. The average T₂ value was determined by            calculating the intensity-weighted average of the peak. R₂            is defined as the inverse of this average T₂, i.e. R₂=1/T₂            and is expressed in Hz. The R₂* for a given mixture is            calculated as the difference between the R₂ of the mixture            and R₂ of the matrix reference sample. Thus, R₂* is a            measure for the bulk water interaction with the available            fiber surface (K. R. Brownstein, C. E. Tarr, Journal of            Magnetic Resonance (1969) Volume 26. Issue 1, April 1977,            Pages 17-24). The characterization of the citrus fibers and            compositions of the Examples and Comparative Experiments in            terms of their R₂* is presented in Table 1c.    -   Rheology Measurements        -   Sample preparation far rheology measurements: dispersions            were made by rehydrating in a buffer solution the milled and            sieved samples. Dispersions with 0.2 wt % and 2.0 wt % fiber            concentrations were prepared. The buffer solution was            obtained by dissolving 40.824 grams of KH₂PO₄ in 2500 g of            demineralized water using a magnetic stir bar. The pH of the            buffer solution was raised to 7.0 by adding drops of 5M NaOH            solution, after which demineralized water was added to            obtain a total of 3000 gram of buffer solution. Each            dispersion was prepared by weighing the appropriate amount            of sample (correcting for moisture and if applicable            additive content) in 500 ml plastic pots followed by            addition of buffer solution to a total weight of 300 g. The            sample was mixed with the buffer solution by mild stirring            using a spoon. Subsequently, two different conditions were            used to facilitate the dispersion. In one series of            experiments, each dispersion was mixed with a Silverson L4RT            overhead hatch mixer equipped with an Emulsor Screen (with            round holes of 1 mm diameter) for 2 min at 3000 rpm. In            another series of experiments, each dispersion was treated            with the same mixer for 10 min at 8000 rpm.        -   Measurements of G′, YS and kinematic viscosity: the            measurements were performed using an ARG2 rheometer from TA            Instruments Ltd UK equipped with sand-blasted stainless            steel parallel plates of 40 mm diameter and operated at a            temperature of 20° C. using a measurement gap of 1.000 mm.            To ensure that measurements are carried out on            representative samples, the samples were gently stirred            using a teaspoon just before placing an aliquot of the            sample in the rheometer. The rheological analysis was            carried out using a standard protocol including a time            sweep, continuous ramps (up and down) of the shear rate and            a strain sweep with the following settings:            -   Time sweep: delay 10 s, 5 min 0.1% strain at 1 Hz;            -   Continuous ramp step1: 0.1 to 500 s⁻¹ shear rate                duration 2 min; mode: log sampling: 10 point/decade;            -   Continuous ramp step2: 500 to 0.1 s⁻¹ shear rate                duration 2 min; mode: log sampling: 10 point/decade;            -   Strain sweep: Sweep: 0.1 to 500 % Strain at 1 Hz,                duration 2 min; mode: log sampling: 10 point/decade.        -    The data analysis software package form TA Instruments            allowed extracting the storage modulus G′, the kinematic            viscosity and the yield stress (YS). G′ is reported at the            time of 300 seconds. The kinematic viscosity is reported at            a shear rate of 22 s⁻¹ (down curve). The YS is determined            from the maximum in the graph of G′ versus strain %, and is            defined as YS=G′×strain. The characterization of the citrus            fibers and compositions of the Examples and Comparative            Experiments in terms of G′, viscosity and YS, are summarised            in Tables 2 and 3.        -   Self-suspending capacity (SSC): 100 ml of a dispersion            having 0.1 wt % fibre content was prepared as presented            above in the “Rheology measurements” section. The dispersion            was carefully poured to avoid air entrapping into a 100 ml            graded glass measuring cylinder while keeping the cylinder            slightly tilted. The top of the cylinder was closed using            para-film. The closed cylinder was slowly shaken by tilting            it ten times to mix and to remove any air bubbles that might            be trapped in the dispersion. The cylinder was stored at            room temperature and the fibers were allowed to settle under            gravity. After 24 hours, SSC was determined by measuring the            volume occupied by the fibers as determined by optical            inspection and expressing it as a percentage from the total            volume. Values are reported in Table 1. The higher the            volume, the higher and thus better the SSC of the sample.        -   Viscosity ratio measurements indicating the ability of a            fiber sample to develop its functionality on low shearing            were made as follows: dispersions were prepared as presented            above in the “Rheology measurements” section. A first            viscosity was measured on the dispersions following the            methodology presented in the “Rheology measurements”.            Subsequently, the dispersions were passed through a            homogenizer at 250 bars and allowed to rest for about 1 hour            at 20° C. to reach their equilibrium state. A second            viscosity was measured under the same conditions as            previously presented. The ratio of the first viscosity to            the second viscosity is used as an indicator of the sample's            capacity to reach functionality after low shear dispersion.

The invention will now be described with the help of the followingexamples and comparative experiments, without being however limitedthereto.

EXAMPLE 1

Dry citrus fibers were manufactured as follows:

Step (1) Water was added to de-pectinized citrus peel (a by-product of apectin extraction process) to obtain an aqueous slurry having a drysubstance content of about 4 wt %. The slurry was one time charged to apressure homogenizer (APV homogenizer, Rannie 15-20.56) at 600 bars. Anaqueous slurry containing citrus fibers was obtained.

Step (2) A precipitation tank was filled with an aqueous isopropanolsolution (about 82 wt % isopropanol in water). The aqueous slurrycontaining citrus fibers was brought under agitation into theprecipitation tank by using a volumetric pump and a precipitate in theform of granules having sizes between 5 mm and 50 mm was formed in thetank. The slurry:isopropanol ratio was 1:2. Agitation by stirring wasprovided while bringing said slurry into the tank and the precipitatewas kept in the tank for about 30 minutes.

Step (3) The precipitate was charged to a centrifuge decanter (Flottwegcentrifuge) operated at above 4000 rpm, to separate the liquid phase(i.e. water and isopropanol) from the citrus fibers.

Step (4) Steps (2) and (3) were repeated and the precipitate wassubjected to an extraction step to increase the dry substance content.The extraction step was earned out by feeding the precipitate to a screwpress. The speed and pressure of the press were adjusted to obtain asemi-dry cake having a dry substance content of about 22 wt %.

Step (5) The semi-dry cake was comminuted using a Lodige type FM 300 DMZmixer, for about 15 to 30 minutes, to obtain grains having sizes in therange of 1 millimeter.

Step (6) The comminuted cake was dried in a ventilated oven at 40° C.for about 2 hours to reach a moisture content of about 8 wt %.

The properties of the obtained fibers are presented in Tables 1(a to c)to 3. FIG. 1 shows the T₂ distribution curves resulting from the inverseLaplace transform obtained during NMR data analysis for the sample ofExample 1 and the corresponding matrix reference sample, respectively.

EXAMPLES 2 AND 3

Dry compositions were manufactured as follows:

Example 1 was repeated with the difference that at step (5) thecomminuted semi-dry cake was mixed with commercial sucrose in twosucrose:fiber ratios of 0.4:1 and 7:1, respectively. Before adding it,the commercial sucrose was milled to an average particle size of about250 μm.

The properties of the obtained compositions are presented in Tables 1(ato c) to 3.

FIG. 2 shows the T₂ distribution curves resulting from the inverseLaplace transform obtained during NMR data analysis for the sample ofExample 2 and the corresponding matrix reference sample, respectively.

Comparative Experiment 1

A dry composition was manufactured as follows:

Step (1) Water was added to de-pectinized citrus peel to obtain anaqueous slurry having a dry substance content of about 4 wt %. Theslurry was charged to a pressure homogenizer (APV homogenizer, Rannie15-20.56) at 600 bars. An aqueous slurry containing citrus fibers wasobtained.

Step (2) The aqueous slurry containing citrus fibers was subjected to anextraction step with a screw press to increase the dry substance contentto a level of about 22% wt %.

Step (3) The semi-dry cake was dried on an plate in an oven at 40° C.for several days to reach a moisture content of about 8 wt %.

The properties of the obtained fibers are presented in Tables 1(a to c)to 3.

Comparative Experiment 2 and 3

Example 1 of U.S. Pat. No. 6,485,767 was repeated. Commercial sucrose intwo sucrose:fiber ratios of 0.1:1 and 5:1, respectively, was used asadditive and added using a paddle mixer and mixed for 30 minutes. Thesucrose had an average particles size of about 250 (?) μm.

The properties of the obtained fibers and compositions are presented inTables 1(a to c) to 3. The comparative composition having a 5:1sucrose:fiber ratio, cannot be prepared for measurements like the othersamples due to increased stickiness and it was discarded.

Self-Suspending Capacity, R₂* and FAP Values

TABLE 1a SSC (%) Ex.1 19 Ex.2 21 Ex.3 21 CE.1 3 CE.2 7 CE.3 Notmeasurable

TABLE 1b FAP determination R₂(sample) (Hz) R₂(matrix) (Hz) FAP (Hz) Ex.10.79 0.41 0.37 Ex.2 1.16 0.42 0.74

As defined in the protocol above, the FAP parameter is determined onsamples prepared and analyzed in the same way as described for themethod of measurement for R₂*, with the only difference being thatduring sample preparation, the mixtures containing the inventive fibersor compositions in water were homogenized at 1500 rpm. However, it wasnot possible to measure FAP on the samples made according to thecomparative experiments, since these samples did not disperse well andor did not stay in dispersion long enough to allow for the measurementto take place.

To enable the NMR characterization on the samples of comparativeexperiments, R₂* measurements were carried out on samples dispersed at3000 rpm rather than 1500 rpm. The results are presented in Table 1c.

TABLE 1c R₂ * (Hz) dispersing at 3000 rpm Ex.1 1.242 Ex.2 1.23 Ex.30.949 CE.1 0.297 CE.2 0.626 CE.3 Not measurable

The fact that NMR measurements were only possible after dispersing thesamples of the comparative experiments at higher rpms (thus highershear) may be an indication of a larger available free-surface area forthe fibers of the invention than that of known fibers.

Rheology Measurements

Samples of the above fibers and compositions were dispersed in water bystirring under the conditions mentioned in Tables 2 and 3 to obtain twofiber concentrations, i.e. 2 and 0.2 wt % of fibers in water,respectively. The rheology data are presented in said Tables 2 and 3.

It was observed that the inventive compositions have an optimalviscoelastic stability, e.g. fewer fluctuations of compositions'viscoelastic behavior. While the STDEV of the inventive compositionswere systematically below 50% of MAX. those of the comparativeexperiments could not even be determined since the comparative samplehaving 5:1 sucrose:fiber ratio was not processable for the measurements.This is believed to demonstrate the ability of the inventivecompositions to smoothen out viscoelastic fluctuations, which in turnmay indicated a more reliable processing thereof.

It was also observed that the inventive compositions had greater R₂*values than the known compositions which was believed to indicate thatthe additive is optimally distributed between the citrus fibers and alsobetween the micro fibrils funning the citrus fibers. This in turnconferred to the inventive composition unique viscoelastic propertieseven at concentration of citrus fibers as low as 0.2 wt % therebyproviding economy and ease of formulation, while still providing thenecessary rheological behavior.

It was also observed that the inventive compositions had greater FibreAvailability Parameter (FAP) values than the known compositions whichstrengthened the belief that the additive is optimally distributedbetween the citrus fibers and also between the microfibrils forming thecitrus fibers.

In particular it was observed that it may be possible to readilydisperse the inventive composition by applying low levels of shear (e.g.3000 rpm) and even lower, for short periods of time (e.g. 2 minutes)while providing homogeneity and stability of a wide variety ofsuspensions, such as those of the types used in foods, cosmetics,pharmaceuticals, but also those used in industrial products, such aspaints and drilling muds.

From the presented data can also be observed that the fibers andcompositions made in accordance with the invention were able to provideoptimal rheological properties at extremely low concentrations e.g. 0.2wt %. In contrast thereof, fibers and compositions prepared inaccordance with the prior an failed to influence the rheologicalbehavior of dispersions containing them at such low concentration.

Moreover, although readily dispersible at low shear levels, the fibersand compositions of the invention were extremely effective in providingoptimum rheological properties to dispersions containing thereof alsowhen dispersed under increased shear levels (e.g. 8000 rpm) for longerperiod of lime (e.g. 10 min). Although herein called longer period oftime, it is to be noted that 10 minutes is shorter than the time used inthe prior art to disperse fibers.

Surprisingly, all of the above mentioned advantages were achieved withsubstantially chemically or enzymatically unmodified citrus fibers.

EXAMPLE 4 AND COMPARATIVE EXAMPLE 4

Ready to drink tea beverages comprising citrus fibers, homogenized withdifferent shear treatments were prepared using a method according to theinvention and using a comparative method, respectively.

Citrus Fibers

For Example 4 (Ex. 4), the dry composition as described in Example 2,comprising citrus fibers and having a sucrose content of 28.6% (w/w) wasused. Herbacel AQ+ citrus fibers were used in the comparative example(CE4).

Preparation of the Ready to Drink Milk Tea

Milk tea ingredients were combined with hot Millipore water of 90° C. asdetailed in Table 4 to form 800 grams of ready-to-drink milk tea.

TABLE 4 CE 4 Ex. 4 Ingredient (grams) (grams) sucrose 51.36 51.04creamer 14.48 14.48 Black tea powder 2.15 2.15 Herbacel AQ+ 0.86Composition of Ex 2 1.20 Water balance balance

The milk tea compositions were homogenized with an overhead SilversonL4RT-A mixer equipped with a small grid, 1 mm holes head during 5minutes at 3000 rpm. Part of the milk tea compositions was used todetermine particle size directly after the Silverson treatment (Ex. 4,and CE4, respectively) and another part was homogenized in a Gea NiroSoavi Panda Plus High Pressure Homogenizer in one pass at 250 bar (Ex 5and CE5, respectively), as detailed in Table 5.

TABLE 5 Shear treatment CE4 CE5 Ex. 4 Ex. 5 Silverson y y y y HPH 250bar y y

Particle size of the ready to drink milk tea samples (without anypretreatment such as e.g. sonication) was determined with a MalvernMastersizer 2000 anti expressed as d (0.1), d (0.5) and d (0.9) in table6.

The value of d(0.5) is the diameter of the volume-equivalent spherecorresponding to the volume-weighted median particle volume (that is,half of the total volume of the dispersed material is made up ofparticles with a volume smaller than or equal to the median volume andhalf of the total volume of dispersed material has a larger volume).Correspondingly d(0.9) is the value where 90% of the total volume of thedispersed material is made up of particles with volumes smaller or equalto the volume of a sphere with this diameter and d(0.1) is the valuewhere 10% of the total volume of the dispersed material is made up ofparticles with volumes smaller or equal to the volume of a sphere withthis diameter.

TABLE 6 d (0.1) [μm] d (0.5) ) [μm] d (0.9) ) [μm] CE 4 30.077 79.433172.262 CE 5 21.531 67.250 160.153 Ex 4 0.176 23.975 87.929 Ex 5 0.1060.327 38.141

The difference in particle size between the Examples 4 and 5 accordingto the invention and the Comparative Examples CE4 and CE5 indicates thatthe physical stability of the products comprising the inventivecomposition of matter in dry form comprising citrus fibres and sucroseis higher than that of the comparative samples and that smaller particlesizes can be obtained with the inventive composition, even with theapplication of lower amounts of shear. Thus, these examples demonstratethat the method for preparing a composition comprising an aqueous phasecomprising dispersed citrus fibres according the invention can be usedto prepare an oil-in-water emulsion, such as an RTD milk tea withfavourable properties, using a relatively limited amount of shear energyduring product manufacture.

EXAMPLES 6 AND 7 AND COMPARATIVE EXAMPLES 6 and 7

Hand dish wash (HDW) surfactant formulations structured with differentcitrus fibre preparations were compared and investigated in terms oftheir theological properties. Example 6 was structured with the drycitrus fibres of Example 1 above. Example 7 was structured with thecomposition of matter in dry form of Example 2 above, which contained28.6 % sucrose. Comparative example CE6 comprised non-defibrillatedcitrus fibre (Herbacel AQ+ type N, Herbafood, Germany). ComparativeExample CE7 was prepared with Herbacel AQ+ type N citrus fibre materialthat was defibrillated using a high pressure homogeniser (Panda NS1001L,Niro-Soavi, Parma, Italy) operated at 200 bar. The preparation of thesamples is discussed below. The formulations of the Example compositions6, 7, CE6, and CE7 are provided in Table 7.

The theology of the samples was analysed with a controlled stressrheometer (TA-AR 2000ex, TA instruments, Delaware, US) fitted with asandblasted plate geometry (sandblasted plate diameter 40 mm, gap 1.5mm) to obtain viscoelastic moduli (G′) by a time sweep oscillation of 5min at 20° C. with a strain of 0.1% and frequency of 1 Hz.

In addition, the ability to suspend particulates was investigated bystirring 1 wt % olive stone abrasive (16-30 mesh) into aliquots of eachof the 4 samples, transferring these in 4 measured cylinders, andperforming an accelerated stability test by storage of the samples in atemperature regulated cabinet at 45° C. At days 0, 3, and 5 the volumeof the sedimented particles was recorded and expressed as % sediment bycomparison to the total product volume. Results are presented in Table9.

Preparation of Samples:

The hand dishwash compositions were made following the below preparationinstructions:

-   -   1. Add demi-water in a beaker.    -   2. Add an equivalent of 0.25 wt % of citrus fibre material and        hydrate with overhead paddle stirrer for 20 minutes (model RW27,        IKA-Werke, Germany).    -   3. Add NaOH while mixing.    -   4. Add LAS acid while mixing.    -   5. Add SLES and mix until dissolved.    -   6. Add preservative while mixing.    -   7. Adjust pH between 6-7 using NaOH or citric acid.    -   8. For Examples 6 and 7, and comparative example CE6: Shear the        whole formulation by single passage through an in-line Silverson        at 8000 rpm using a flow of 300 ml/min.    -   9. For Comparative Example CE7: Shear the whole formulation by        single passage through a high pressure homogeniser at 200 bar.    -   10. Add MgSO4.7H2O and mix until dissolved.

TABLE 7 Formulations of Ex 6, Ex7, CE6, and CE7. Ex 6 Ex 7 CE7, CE8Ingredients (% wt) (% wt) (% wt) Demineralised water 76.98 76.88 76.98Citrus Fibre of Ex. 1 0.25 — — Citrus Fibre preparation — 0.35 — of Ex.2Herbacel AQ+ type N — — 0.25 NaOH (50%) 3.23 3.23 3.23 LAS acid (97%)11.60 11.60 11.60 SLES IEO (70%) 5.36 5.36 5.36 Nipacide BIT 20preservative 0.08 0.08 0.08 MgSO4•7H2O 2.50 2.50 2.50 Total 100.00100.00 100.00

The results of the rheological measurements in Table 8 show that the HDWproduct of CE7, structured with reference material Herbacel AQ+ astreated above resulted in the lowest G′ and yield stress values.

The use of pre-defibrillated citrus fibre material of Ex. 7 in a HDWformulation and further activation by an in-line Silverson mixer,significantly improved G′ and yield stress of the HDW product.

The highest G′ and yield stress value was obtained for the HDW productof Ex 7, structured with the citrus fibre preparation of Ex. 2.Stabilising the pre-defibrillated primary cell wall material used in Ex7 with sucrose clearly further enhanced its structuring ability upon lowshear activation.

Comparison shows that Example 6 exhibited a similar G′ value as CE 7.However, Ex. 6 did not require high pressure homogenisation at 200 baras CE7 did.

TABLE 8 G′ (viscoelastic modulus) and yield stress of HDW productsstructured with citrus fibre material G′ (Pa), Yield stress (Pa), n = 2SD* n = 2 SD* CE 6 1.34 ±0.01 0.03 ±0.023 Ex 6 5.64 ±0.08 0.13 ±0.001 Ex7 9.19 ±0.23 0.24 ±0.004 CE 7 5.53 ±0.51 0.06 ±0.012 *SD = standarddeviation

The accelerated suspension results of olive stones in the HDW productsin Table 9 show that the suspending ability of the various samplesfollowed the rheological behaviour of these samples as outlined in Table8. The higher the G′ and yield stress of the sample, the better itsolive stone suspending properties. Ex. 7 provided the best suspensionresults.

TABLE 9 Accelerated suspension test at 45° C. of HDW products structuredwith citrus fibre material holding 1 wt % olive stone abrasive particlesOlive stone suspending ability of HDW products (ml ± SD) day 0 day 3 day5 day 15 CE 6 100 3.5 ± 0.7 3.2 ± 0.9 2.7 ± 0.5 Ex 6 100 89.4 ± 0.2 81.2 ± 2.6  68.2 ± 2.1  Ex 7 100 97.0 ± 0.1  89.1 ± 1.6  75.5 ± 0.1  CE7 100 82.6 ± 3.2  73.1 ± 0.2  60.3 ± 0.9 

In conclusion, it was shown that citrus fibre material of the presentinvention only requires low shear activation to achieve similar or evensuperior product structure, whereas products structured with traditionalcitrus fibre—processed in the same way, or at higher shearactivation—showed inferior structure.

TABLE 2 Rheology 1 Rheology 2 (2 minuntes at 3000 rpm) (10 minuntes at8000 rpm) Fiber % % Sucrose: Drying Moisture Sample conc. σ(‡) of η atσ(‡) of η at fiber time (o) content weight (***) G' of MA YS 22⁻¹ sec G'of MA YS 22⁻¹ sec ratio (min) (*) (%) (**) (%) (%) (Pa) G' X (PA) (Pa ·s) (Pa) G' X (PA) (Pa · s) Ex. 1   0:1 120 8 229 2 172 108 29 2.3 0.74484.6 91 15 10.6 2.26 Ex. 2 0.4:1 120 290 367(†) 5.0 1.47 604.7(†) 14.32.74 Ex. 3   7:1 180 1279 191 3.1 0.82 426.8 8.8 1.85 CE. 1   0:1 1440214 0.11 — — 0.04 0.004 17.95 — — 0.2 0.10 CE. 2 0.4:1 1440 314 2.59 0.40.02 155.7 1.5 0.60 CE. 3   5:1 4320 1256 N/M N/M N/M N/M N/M N/M (o) =drying time to reach the mentioned moisture content. (*) = moisture-scontent of the dry composition. (**) = sample's weight, i.e. the weightof the dispersed dry composition in water, used for rheologicalmeasurements. (***) = citrus fiber's concentration in the dispersedcomposition in water. (†) = MAX (‡) = STDEV N/M = not measurable

TABLE 3 Rheology 1 Rheology 2 (2 minuntes at 3000 rpm) (10 minuntes at8000 rpm) Fiber % % Sucrose: Drying Moisture Sample conc. σ(‡) of η atσ(‡) of η at fiber time (o) content weight (***) G' of MA YS 22⁻¹ sec G'of MA YS 22⁻¹ sec ratio (min) (*) (%) (**) (%) (%) (Pa) G' X (mPA) (mPa· s) (Pa) G' X (mPA) (mPa · s) Ex. 1   0:1 120 8 229 0.2 0.14 0.03 16 284.6 2.867 1.05 27 208 27.1 Ex. 2 0.4:1 120 290 0.17 56 7.9 3.903(†) 24832.8 Ex. 3   7:1 180 1279 0.20(†) 40 5.1 1.809 241 22.3 CE. 1   0:1 1440214 0.01 — — N/M 1.9 0.068 — — 10 2.8 CE. 2 0.4:1 1440 314 0.07 N/M 2.30.0924 10 6.0 CE. 3   5:1 4320 1256 N/M N/M N/M N/M N/M N/M (o) = dryingtime to reach the moisture content of 8%. (*) = moisture content of thedry composition. (**) = sample's weight, i.e. the weight of thedispersed dry composition in water, used for rheological measurements.(***) = citrus fiber's concentration of? the dispersed composition inwater. (†) = MAX (‡) = STDEV N/M = not measurable

1-15. (canceled)
 16. Cellulose fibers in dry form having aself-suspending capacity (“SSC”) of at least 8%, and comprising anadditive distributed between said fibers.
 17. The cellulose fibers ofclaim 16, wherein the cellulose fibers in dry form have an SSC of atleast 12%.
 18. The cellulose fibers of claim 17, wherein the cellulosefibers in dry form have an SSC of at least 15%.
 19. The cellulose fibersof claim 18, wherein the cellulose fibers in dry form have an SSC of atleast 17%.
 20. The cellulose fibers of claim 19, wherein the cellulosefibers in dry form have an SSC of at least 19%.
 21. The cellulose fibersof claim 16, wherein the cellulose fibers in dry form are citrus fruitfibers in dry form.
 22. The cellulose fibers of claim 16, wherein thecellulose fibers in dry form have a moisture content of at most 12 wt.%.
 23. The cellulose fibers of claim 16, wherein said cellulose fibersin dry form are derived from at least one of oranges, sweet oranges,clementines, kumquats, tangerines, tangelos, satsumas, mandarins,grapefruits, citrons, pomelos, lemons, rough lemons, limes, and leechlimes.
 24. The cellulose fibers of claim 16, wherein said cellulosefibers in dry form are derived from at least one of early-season,mid-season, and late-season citrus fruit.
 25. The cellulose fibers ofclaim 16, wherein said cellulose fibers in dry form are derived from atleast one of citrus peel, citrus pulp, and citrus rag.
 26. The cellulosefibers of claim 16, wherein said cellulose fibers in dry form are notsubjected to at least one of esterification, derivatization, andenzymatic modification.
 27. The cellulose fibers of claim 16, whereinthe cellulose fibers in dry form comprise at least 5 wt. % additiverelative to the weight of the cellulose fibers in dry form,
 28. Thecellulose fibers of claim 16, wherein the additive to cellulose fibersin dry form ratio is between 0.01:1.0 and 10.0:1.0 by weight.
 29. Thecellulose fibers of claim 16, wherein the additive is one or morecarbohydrates or polyols.
 30. The cellulose fibers of claim 16, whereinthe additive is at lease one of glucose, sucrose, glycerol, andsorbitol.
 31. A food composition comprising the cellulose fibers ofclaim 16, wherein said food composition is chosen from the groupconsisting of luxury drinks, milk component-containing drinks,nutrition-enriched drinks, dairy products, iced products, processed fatfood products, soups, stews, seasonings, paste condiments, fillings,gels, paste-like food products, food products containing cereals as themain component, cakes, kneaded marine products, live-stock products,daily dishes, foods of delicate flavor, liquid diets, supplements andpet foods.
 32. An emulsified product comprising the cellulose fibers ofclaim 16 and one or more proteins.
 33. The emulsified product of claim32, wherein the emulsified product comprises one or more proteins inabout 0.1 wt. % to about 10.0 wt. % of the emulsified product.
 34. Acomposition comprising the cellulose fibers of claim 16 and one or moresurfactants.